Welcome to our MCQs Assessment series! In this post, we provide the Veterinary Pharmacology and Toxicology MCQs With Answers to help you evaluate your understanding and mastery of Veterinary Pharmacology and Toxicology. Here you may not only be able to practice these questions but we have also provided the direct link through which you can download these MCQs in PDF format. These questions are designed to cover key concepts and topics within the subject area, serving as an excellent resource for self-assessment and review.
Principles of Drug Absorption, Drug Disposition, and Drug Action
1. What is P-glycoprotein’s role in drug excretion?
a) Enhances drug absorption
b) Acts as a transmembrane efflux pump
c) Inhibits drug metabolism
d) Enhances renal filtration
2. Which drugs are known substrates of P-glycoprotein?
a) Aspirin and ibuprofen
b) Tylosin and erythromycin
c) Digoxin and doxorubicin
d) Amoxicillin and penicillin
3. Why is milk an important route for drug excretion in dams?
a) It allows for drug concentration measurement
b) It leads to ion trapping
c) It produces residues that require a withdrawal period
d) It increases drug metabolism
4. What is the effect of copious salivation in herbivores on drug excretion?
a) It enhances drug absorption
b) It disrupts digestive processes in the rumen
c) It increases drug metabolism
d) It leads to rapid drug clearance
5. Which route of drug elimination is primarily important for volatile drugs?
a) Milk
b) Saliva
c) Expired air
d) Sweat
6. What is the definition of bioavailability
a) The fraction of drug eliminated unchanged
b) The fraction of drug entering the systemic circulation intact
c) The volume of blood cleared of a drug per unit time
d) The concentration of drug in the plasma
7. What is the apparent volume of distribution ?
a) The actual volume of blood in the body
b) A proportionality constant relating plasma drug concentration to the total amount of drug in the body
c) The rate at which a drug is metabolized
d) The fraction of drug absorbed from the site of administration
8. What factor primarily determines the total body clearance (ClB) of a drug?
a) The drug’s solubility in water
b) The volume of distribution
c) The bioavailability
d) The volume of blood cleared of a drug in a specified period of time
9. Which species are more sensitive to xylazine and why?
a) Cattle, due to α2D-receptors
b) Dogs, due to α2A-receptors
c) Cats, due to α2B-receptors
d) Horses, due to α2C-receptors
10. What causes CNS depression in collies when administered normal doses of ivermectin?
a) A defect in the P-glycoprotein transporter
b) High levels of liver enzymes
c) Enhanced renal clearance
d) Increased drug absorption
11. Why should ivermectin not be used in tortoises and crocodiles?
a) Potential toxic effects
b) Rapid drug metabolism
c) Slow drug absorption
d) High bioavailability
12. What is the half-life of aspirin in cats compared to dogs and horses?
a) 1 hour in cats, 25–35 hours in dogs, 8 hours in horses
b) 25–35 hours in cats, 8 hours in dogs, 1 hour in horses
c) 8 hours in cats, 1 hour in dogs, 25–35 hours in horses
d) 25–35 hours in cats, 1 hour in dogs, 8 hours in horses
13. What happens to drugs that are basic in milk compared to plasma?
a) They become more ionized in plasma
b) They diffuse back into the plasma
c) They become trapped in milk due to ion trapping
d) They are eliminated more rapidly
14. What is the primary elimination process for quaternary drugs?
a) Renal reabsorption
b) Rapid elimination due to polarity
c) Hepatic metabolism
d) Biliary secretion
15. What is enterohepatic recycling?
a) Reabsorption of drug conjugates eliminated via bile
b) Rapid elimination of drugs through the kidney
c) Binding of drugs to plasma proteins
d) Metabolism of drugs in the intestine
16. What effect does liver disease have on the pharmacokinetics of lipophilic drugs?
a) Increases metabolism
b) Decreases duration of action
c) Reduces microsomal activity
d) Enhances renal clearance
17. Which drugs have a larger volume of distribution in ruminants compared to non-ruminants?
a) Hydrophilic drugs
b) Ionized drugs
c) Lipophilic organic bases
d) Acidic drugs
18. What causes the variability in the half-life (t 1/2) of trimethoprim in carp at different temperatures?
a) Renal function
b) Biliary secretion
c) Ambient temperature affecting metabolic rate
d) Drug absorption rate
19. What is the primary factor affecting drug distribution in cold-blooded animals?
a) High metabolic rates
b) Rapid renal clearance
c) Lower renal function and more enterohepatic recycling
d) Increased liver metabolism
20. What is the main consequence of drug–protein binding?
a) Prevention of drug reaching the site of action
b) Acceleration of drug elimination
c) Slowing the rate at which a drug reaches a pharmacologic effect
d) Increasing drug absorption
21. How is the drug response terminated in drugs exhibiting redistribution?
a) Metabolism only
b) Redistribution from the site of action to other tissues
c) Increased renal clearance
d) Decreased plasma concentration
22. Why do lean breeds like Greyhounds take longer to recover from lipophilic anesthetics?
a) Rapid liver biotransformation
b) Higher plasma concentrations
c) Less fat for the anesthetics to redistribute to
d) Increased renal clearance
23. What type of drugs cross the placenta best?
a) Ionized drugs
b) Hydrophilic drugs
c) Lipid-soluble drugs
d) Acidic drugs
24. How does fever affect the pharmacokinetics of drugs like penicillins?
a) Decreases extravascular distribution
b) Increases renal clearance
c) Increases the permeability of inflamed tissue barriers
d) Enhances drug absorption
25. Which drugs are likely to show less species variation in their half-life (t 1/2) values?
a) Lipid-soluble drugs
b) Highly ionized drugs
c) Basic drugs
d) Neutral drugs
26. Why do fish have longer half-life values compared to mammalian species?
a) Higher metabolic rates
b) Increased renal clearance
c) Lower metabolic rates
d) Enhanced drug absorption
27. What happens to drugs that are bound to albumin in terms of elimination?
a) They are eliminated more rapidly
b) They remain in the systemic circulation longer
c) They are eliminated via bile
d) They are rapidly metabolized
28. What is the effect of reduced serum albumin levels on drug pharmacokinetics?
a) Increased drug binding to plasma proteins
b) Decreased free drug concentration
c) Increased free drug concentration
d) Enhanced drug elimination
29. A 5-year-old dog is administered digoxin. What should be monitored due to its P-glycoprotein substrate status?
a) Liver enzyme levels
b) Renal function
c) Cardiac function
d) Neurological signs
30. A dairy cow is given an antibiotic that can be excreted in milk. What is the primary concern?
a) Efficacy of the drug
b) Residues in milk
c) Drug metabolism
d) Rapid clearance
31.A collie exhibits CNS depression after receiving a normal dose of ivermectin. What is the likely cause?
a) High doses of ivermectin
b) Defective P-glycoprotein
c) Slow metabolism
d) Enhanced absorption
32. A tortoise is treated with ivermectin and develops toxicity. What is a likely factor?
a) Rapid metabolism
b) High bioavailability
c) Slow drug clearance
d) Poor absorption
33. A cat receives aspirin with a half-life of 25–35 hours. How does this compare to dogs and horses?
a) Shorter than both
b) Longer than both
c) Shorter than dogs, longer than horses
d) Longer than dogs, shorter than horses
34. A nursing dam is given a basic drug. Where is the drug likely to concentrate?
a) Plasma
b) Liver
c) Milk
d) Kidneys
35. A patient on quaternary drugs (R4−N+) exhibits rapid drug clearance. What is the reason?
a) Hepatic metabolism
b) Renal reabsorption
c) Rapid elimination due to polarity
d) Increased bioavailability
36. A dog treated with a drug showing enterohepatic recycling has prolonged effects. What causes this?
a) Rapid renal clearance
b) Slow absorption
c) Reabsorption of drug conjugates eliminated via bile
d) High bioavailability
37. A drug in a two-compartment model shows initial rapid decline in plasma concentration. What does this represent?
a) Distribution phase
b) Metabolic phase
c) Elimination phase
d) Absorption phase
38. A patient with liver disease has altered drug pharmacokinetics. What is affected?
a) Increased renal clearance
b) Enhanced drug absorption
c) Reduced microsomal activity
d) Accelerated drug metabolism
39. A ruminant is given a lipophilic organic base. How does its volume of distribution compare to non-ruminants?
a) Smaller
b) Larger
c) Equal
d) Negligible
40. A carp exhibits different half-life values for trimethoprim at various temperatures. What factor affects this?
a) Ambient temperature affecting metabolic rate
b) Renal function
c) Biliary secretion
d) Drug absorption rate
41. A cold-blooded animal shows slow drug clearance. What is the primary reason?
a) High metabolic rates
b) Lower renal function and more enterohepatic recycling
c) Rapid renal clearance
d) Enhanced liver metabolism
42. A drug bound to albumin has prolonged effects. What is the consequence of drug–protein binding?
a) Rapid elimination
b) Slowing the rate at which a drug reaches a pharmacologic effect
c) Increased drug absorption
d) Prevention of drug reaching the site of action
43. A dog shows prolonged recovery from lipophilic anesthetics. What could be the reason?
a) Rapid liver biotransformation
b) Higher plasma concentrations
c) Less fat for the anesthetics to redistribute to
d) Increased renal clearance
44. A pregnant animal is administered a drug. What type of drug crosses the placenta best?
a) Ionized drugs
b) Hydrophilic drugs
c) Lipid-soluble drugs
d) Acidic drugs
45. A patient with fever is given penicillin. What effect does fever have on drug pharmacokinetics?
a) Decreases extravascular distribution
b) Increases renal clearance
c) Increases the permeability of inflamed tissue barriers
d) Enhances drug absorption
46. A fish shows prolonged drug half-life compared to mammals. What is a key factor?
a) Higher metabolic rates
b) Lower metabolic rates
c) Increased renal clearance
d) Enhanced drug absorption
47. A collie with a defective P-glycoprotein gene is given ivermectin. What is a possible outcome?
a) Enhanced drug clearance
b) Reduced drug metabolism
c) CNS depression
d) Increased absorption
48. A dairy cow given a lipophilic drug shows residues in milk. What is the likely reason?
a) Rapid drug metabolism
b) Ion trapping in milk
c) Enhanced renal clearance
d) Slow drug absorption
49. A carp’s drug half-life varies with temperature changes. What is a primary cause?
a) Biliary secretion
b) Ambient temperature affecting metabolic rate
c) Renal function
d) Drug absorption rate
50. A dog is given a drug with enterohepatic recycling. What is an expected outcome?
a) Rapid elimination
b) Prolonged drug effects
c) High plasma concentration
d) Increased bioavailability
51. A ruminant receives a drug with a larger volume of distribution compared to a non-ruminant. What type of drug is it likely to be?
a) Hydrophilic drug
b) Ionized drug
c) Lipophilic organic base
d) Acidic drug
52. A veterinarian administers an anesthetic to a Greyhound. What could prolong the recovery time?
a) Rapid liver biotransformation
b) High plasma concentration
c) Less fat for redistribution
d) Increased renal clearance
53. A cat shows prolonged aspirin half-life compared to dogs and horses. What is the half-life in cats?
a) 1 hour
b) 8 hours
c) 25–35 hours
d) 10 hours
54. A pregnant animal receives a lipid-soluble drug. What is a concern regarding drug transfer?
a) Drug absorption
b) Placental transfer
c) Renal clearance
d) Drug metabolism
55. A dog with reduced serum albumin levels is given a drug. What effect on pharmacokinetics is expected?
a) Increased drug binding to plasma proteins
b) Decreased free drug concentration
c) Increased free drug concentration
d) Enhanced drug elimination
56. A veterinarian is treating a collie known to have a defective P-glycoprotein gene. The dog needs an antiparasitic treatment, but the veterinarian decides against using ivermectin. What could be the reason?
a) Enhanced absorption
b) Risk of CNS depression
c) Poor efficacy
d) Rapid clearance
57. A farmer is concerned about antibiotic residues in milk after treating a cow. The veterinarian explains that basic drugs tend to concentrate in milk due to ion trapping. What does ion trapping refer to in this context?
a) Enhanced drug absorption
b) The trapping of drugs in milk due to pH differences
c) Rapid drug clearance
d) Increased drug metabolism
58. A Greyhound recovers slowly from anesthesia with a lipophilic anesthetic. The veterinarian notes that the dog has less fat for drug redistribution. How does this affect the anesthetic recovery?
a) Rapid liver metabolism
b) Higher plasma concentration
c) Slower redistribution from the central compartment
d) Enhanced renal clearance
59. A pregnant cat receives a lipid-soluble drug. The veterinarian advises caution due to potential placental transfer. What property of the drug facilitates this transfer?
a) Ionization
b) Lipid solubility
c) Hydrophilicity
d) High molecular weight
60. A tortoise develops signs of toxicity after being given ivermectin. The veterinarian notes the species-specific response. What characteristic of ivermectin causes this in tortoises?
a) High bioavailability
b) Slow drug clearance
c) Enhanced metabolism
d) Rapid absorption
61. A collie is administered a standard dose of ivermectin. The veterinarian monitors the dog closely for signs of CNS depression. What genetic factor could contribute to this adverse effect?
a) Defective P-glycoprotein
b) Enhanced renal clearance
c) Increased absorption
d) Rapid metabolism
62. A veterinarian treats a dairy cow with an antibiotic and advises a withdrawal period to avoid residues in milk. What principle underlies the need for this withdrawal period?
a) Drug metabolism
b) Drug absorption
c) Drug excretion in milk
d) Rapid drug clearance
63. A carp is given trimethoprim at different ambient temperatures. The veterinarian observes variations in the drug’s half-life. What explains the change in half-life with temperature?
a) Renal function variation
b) Ambient temperature affecting metabolic rate
c) Biliary secretion differences
d) Drug absorption changes
64. A veterinarian treats a dog with a drug that undergoes enterohepatic recycling. What effect does this have on the drug’s pharmacokinetics?
a) Increased renal clearance
b) Prolonged duration of drug action
c) Rapid drug elimination
d) Decreased bioavailability
65. A ruminant is given a lipophilic organic base, and the drug’s volume of distribution is larger compared to non-ruminants. What characteristic of the drug contributes to this observation?
a) Hydrophilicity
b) Lipophilicity
c) High molecular weight
d) Ionization
66. A Greyhound recovers slowly from a lipophilic anesthetic. The veterinarian explains that the dog’s lack of body fat affects the drug’s redistribution. How does this impact the anesthetic’s duration of action?
a) Shortened duration
b) No change in duration
c) Prolonged duration
d) Enhanced clearance
67. A cat receives a drug with a known half-life of 25–35 hours. How does this half-life compare to that in dogs and horses?
a) Shorter than both
b) Longer than both
c) Shorter than dogs, longer than horses
d) Longer than dogs, shorter than horses
68. A pregnant animal receives a drug. The veterinarian considers the drug’s lipid solubility for its potential placental transfer. What is a concern regarding lipid-soluble drugs?
a) Poor absorption
b) High renal clearance
c) High placental transfer
d) Low bioavailability
69. A veterinarian treats a dog with reduced serum albumin levels. The dog receives a highly protein-bound drug. What pharmacokinetic change is likely?
a) Increased drug binding to plasma proteins
b) Decreased free drug concentration
c) Increased free drug concentration
d) Enhanced drug elimination
70. A dog with a defective P-glycoprotein gene shows signs of toxicity after receiving a drug. What is a possible explanation?
a) Enhanced drug clearance
b) Reduced drug metabolism
c) CNS depression due to poor efflux
d) Increased absorption
71. A dairy cow treated with a lipophilic drug shows residues in milk. The veterinarian explains that the drug is trapped in milk due to ion trapping. What does this mean?
a) Rapid drug metabolism
b) Drug concentration in milk due to pH differences
c) Enhanced renal clearance
d) Slow drug absorption
72. A carp’s drug half-life changes with ambient temperature. The veterinarian considers the effect of temperature on metabolic rate. What is the primary factor influencing this change?
a) Renal function
b) Ambient temperature affecting metabolic rate
c) Biliary secretion
d) Drug absorption
73. A dog receives a drug that undergoes enterohepatic recycling. The veterinarian expects prolonged drug effects. What process explains this?
a) Increased renal clearance
b) Reabsorption of drug conjugates eliminated via bile
c) Rapid drug elimination
d) Decreased bioavailability
74. A ruminant has a larger volume of distribution for a lipophilic organic base compared to a non-ruminant. What factor contributes to this observation?
a) Hydrophilicity
b) Lipophilicity
c) Ionization
d) High molecular weight
75. A cat is administered aspirin with a half-life of 25–35 hours. How does this half-life compare to that in dogs and horses?
a) Shorter than both
b) Longer than both
c) Shorter than dogs, longer than horses
d) Longer than dogs, shorter than horses
76. A pregnant animal is given a drug. The veterinarian is concerned about placental transfer. Which drug property enhances this transfer?
a) Hydrophilicity
b) Ionization
c) Lipid solubility
d) High molecular weight
77. A dog with low serum albumin levels receives a highly protein-bound drug. What change in drug pharmacokinetics is expected?
a) Increased drug binding to plasma proteins
b) Decreased free drug concentration
c) Increased free drug concentration
d) Enhanced drug elimination
78. A collie is administered a drug known to be a P-glycoprotein substrate and shows signs of CNS toxicity. What genetic factor could explain this response?
a) Enhanced drug clearance
b) Reduced drug metabolism
c) Defective P-glycoprotein leading to poor efflux
d) Increased absorption
79. A dairy cow treated with an antibiotic exhibits drug residues in milk. What principle explains the presence of these residues?
a) Rapid drug metabolism
b) Ion trapping in milk
c) Enhanced renal clearance
d) Slow drug absorption
80. A carp’s drug half-life is influenced by ambient temperature. What is the underlying factor?
a) Biliary secretion
b) Renal function
c) Drug absorption
d) Ambient temperature affecting metabolic rate
81. A dog treated with a drug showing enterohepatic recycling has prolonged drug effects. What explains this phenomenon?
a) Increased renal clearance
b) Rapid drug elimination
c) Reabsorption of drug conjugates eliminated via bile
d) Decreased bioavailability
82. A ruminant exhibits a larger volume of distribution for a lipophilic organic base compared to a non-ruminant. What contributes to this difference?
a) Ionization
b) High molecular weight
c) Lipophilicity
d) Hydrophilicity
Drugs Affecting the Peripheral Nervous System
1. Which neurotransmitter is released by the axons of the somatic nervous system at the neuromuscular junction?
A) Dopamine
B) Norepinephrine
C) Acetylcholine
D) Epinephrine
2. In the autonomic nervous system, how many neurons are involved in the transmission process from the CNS to the effector tissue?
A) One
B) Two
C) Three
D) Four
3. From which regions do the preganglionic neurons of the sympathetic nervous system originate?
A) Cervical and sacral
B) Thoracic and lumbar
C) Thoracic and sacral
D) Lumbar and cervical
4. What type of receptors do preganglionic neurons of the sympathetic nervous system release acetylcholine onto?
A) Muscarinic receptors
B) Adrenergic receptors
C) Nicotinic receptors
D) Dopamine receptors
5. What neurotransmitter is released by postganglionic neurons of the sympathetic nervous system onto the effector tissue?
A) Acetylcholine
B) Dopamine
C) Epinephrine
D) Norepinephrine
6. Which of the following is true about the location of parasympathetic ganglia?
A) Far from the effector cell
B) Close to the spinal cord
C) In or close to the effector cell
D) In the adrenal medulla
7. Which receptor subtype is associated with a decrease in heart excitability?
A) M1
B) M2
C) M3
D) M4
8. What is the primary function of alpha-1 (α1) adrenergic receptors?
A) Increase heart rate
B) Vasodilation
C) Vasoconstriction
D) Decrease blood pressure
9. Which neurotransmitter does dopamine cause to be released from adrenergic neurons?
A) Epinephrine
B) Norepinephrine
C) Serotonin
D) Acetylcholine
10. D1 receptors, when activated, primarily cause:
A) Vasoconstriction
B) Vasodilation
C) Decreased cardiac output
D) Increased neurosecretion
11. What type of receptors do postganglionic neurons of the parasympathetic nervous system release acetylcholine onto?
A) Nicotinic receptors
B) Adrenergic receptors
C) Muscarinic receptors
D) Dopamine receptors
12. Which receptor subtype is primarily involved in the regulation of dopaminergic neurons in the midbrain?
A) M2
B) M3
C) M5
D) M1
13. Where are NM subtype nicotinic receptors found?
A) CNS neurons
B) Autonomic ganglia
C) Muscle neuromuscular junctions
D) Adrenal medulla
14. The primary effect of β2-receptor activation at low doses of epinephrine is:
A) Vasoconstriction
B) Increased cardiac output
C) Increased skeletal muscle blood flow
D) Decreased heart rate
15. What is the effect of catecholamines on the gastrointestinal smooth muscle?
A) Contraction via β-receptors
B) Relaxation via α2- and β-receptors
C) Contraction via α1-receptors only
D) No significant effect
16. Which enzyme is involved in the metabolism of norepinephrine within the effector cell?
A) Acetylcholinesterase
B) Tyrosine hydroxylase
C) Catechol-O-methyltransferase (COMT)
D) Monoamine oxidase (MAO)
17. Which of the following statements about D2-receptors is true?
A) They are coupled to Gs
B) They stimulate cyclic AMP synthesis
C) They inhibit neuroendocrine release
D) They are found in adipocytes
18. What pharmacologic effect does epinephrine have on the heart?
A) Decreased force of contraction
B) Increased automaticity
C) Decreased excitability
D) Decreased oxygen consumption
19. Which catecholamine does not cross the blood-brain barrier readily?
A) Dopamine
B) Epinephrine
C) Norepinephrine
D) All of the above
20. Uptake-1 mechanism primarily involves the reentry of norepinephrine into:
A) The effector cell
B) The nerve terminal
C) The bloodstream
D) The adrenal medulla
21. A 7-year-old dog presents with symptoms of fear and its hairs are erect. Which receptor is responsible for this physiological response?
A) β1-receptors
B) β2-receptors
C) α1-receptors
D) D2-receptors
22. A pregnant cat shows uterine relaxation. Which receptor is likely mediating this effect?
A) β1-receptors
B) β2-receptors
C) α1-receptors
D) D1-receptors
23. A dog is experiencing bronchospasm. Which of the following drugs would be appropriate to administer for immediate bronchodilation?
A) Norepinephrine
B) Dopamine
C) Epinephrine
D) Dobutamine
24. A cat with open-angle glaucoma needs treatment. Which drug would be appropriate to promote the outflow of aqueous humor?
A) Norepinephrine
B) Epinephrine
C) Dopamine
D) Phenylephrine
25. During a surgical procedure, a veterinarian decides to use a vasopressor that does not increase cardiac stimulation. Which drug should be chosen?
A) Epinephrine
B) Norepinephrine
C) Phenylephrine
D) Isoproterenol
26. A dog in cardiogenic shock needs treatment to increase cardiac output by increasing cardiac contractility. Which drug would be most appropriate?
A) Dopamine
B) Norepinephrine
C) Dobutamine
D) Isoproterenol
27. Which adverse effect is most commonly associated with the use of epinephrine in hyperthyroid patients?
A) Cerebral hemorrhage
B) Anxiety
C) Cardiac arrhythmias
D) Restlessness
28. A dog is being treated for acute heart failure with a drug that primarily affects β1-receptors. Which drug is likely being used?
A) Dopamine
B) Epinephrine
C) Dobutamine
D) Norepinephrine
29. Which drug would be used to control localized hemorrhage when applied topically?
A) Norepinephrine
B) Epinephrine
C) Dopamine
D) Isoproterenol
30. Which metabolic effect is caused by stimulation of β-receptors in the liver?
A) Decrease in blood glucose levels
B) Increase in free fatty acid levels
C) Decrease in lactic acid levels
D) Increase in insulin secretion
31. A dog with primary urinary bladder sphincter incompetence is being treated. Which drug is more commonly used for this condition than ephedrine?
A) Phenylephrine
B) Epinephrine
C) Phenylpropanolamine
D) Norepinephrine
32. Which receptor activation causes vasodilation of the renal vasculature at low infusion rates?
A) α1-receptors
B) β1-receptors
C) D1-receptors
D) D2-receptors
33. What adverse effect is specifically associated with norepinephrine extravasation at the injection site?
A) Anxiety
B) Cardiac arrhythmias
C) Necrosis and sloughing
D) Restlessness
34. A horse with severe asthma-like conditions needs treatment. Which scheduled drug could be used?
A) Epinephrine
B) Norepinephrine
C) Ephedrine
D) Isoproterenol
35. A cat needs a mydriatic agent for an eye examination. Which drug would be appropriate to use?
A) Epinephrine
B) Norepinephrine
C) Dopamine
D) Phenylephrine
36. Which drug is metabolized by COMT and MAO, but MAO is less effective than with epinephrine and norepinephrine?
A) Dopamine
B) Dobutamine
C) Isoproterenol
D) Ephedrine
37. Which effect is associated with the activation of α1-receptors in the spleen, particularly in dogs?
A) Increase in erythrocyte levels
B) Decrease in erythrocyte levels
C) Vasodilation
D) Mydriasis
38. A cat with localized hemorrhage requires treatment. Which drug applied topically will control the hemorrhage?
A) Epinephrine
B) Norepinephrine
C) Dopamine
D) Isoproterenol
39. A dog experiencing acute bronchial constriction needs immediate treatment. Which drug should be administered?
A) Isoproterenol
B) Norepinephrine
C) Dopamine
D) Dobutamine
40. Which receptor activation results in urinary retention by causing the trigone and sphincter of the bladder to contract?
A) β1-receptors
B) β2-receptors
C) α1-receptors
D) D1-receptors
41. Which of the following adverse effects is associated with the systemic use of ephedrine?
A) Hypotension
B) Hypertension
C) Hyperthermia
D) Bradycardia
42. Phenylpropanolamine (PPA) is primarily used for which therapeutic purpose?
A) Bronchodilation
B) Treatment of navicular disease
C) Urinary incontinence
D) Airway obstruction in horses
43. What is the primary mechanism of action for phenylpropanolamine (PPA)?
A) Direct activation of β2-adrenergic receptors
B) Indirect release of norepinephrine
C) Direct activation of α1-adrenergic receptors
D) Inhibition of COMT
44. Which of the following is NOT a known adverse effect of terbutaline in animals?
A) Tachycardia
B) Tremors
C) Hyperthermia
D) Excitation
45. Albuterol is primarily used in veterinary medicine for:
A) Reducing cardiac output
B) Vasodilation in skeletal muscle
C) Bronchodilation
D) Treating laminitis in horses
46. Which β2-adrenergic agonist is used as a bronchodilator and is known for its high pKa value limiting oral absorption?
A) Terbutaline
B) Phenylpropanolamine
C) Clenbuterol
D) Albuterol
47. The elimination half-life of clenbuterol in horses after oral administration is approximately:
A) 2 hours
B) 6 hours
C) 12 hours
D) 24 hours
48. Isoxsuprine is primarily used to treat which condition in horses?
A) Airway obstruction
B) Navicular disease
C) Hypertension
D) Urinary incontinence
49. What is the mechanism of action for ractopamine in cattle and swine?
A) Selective β1-adrenergic agonist
B) Selective β2-adrenergic agonist
C) Non-selective adrenergic agonist
D) α1-adrenergic antagonist
50. Phenoxybenzamine is unique among α1-receptor antagonists because it:
A) Is reversible
B) Is a selective β2-agonist
C) Binds covalently and irreversibly to the receptor
D) Has no effect on blood pressure
51. Which drug is known to have its therapeutic efficacy compromised when administered orally to horses due to poor absorption?
A) Albuterol
B) Clenbuterol
C) Terbutaline
D) Isoxsuprine
52. Which of the following drugs is noted for causing anorexia as a side effect in animals?
A) Terbutaline
B) Ractopamine
C) Phenylpropanolamine
D) Clenbuterol
53. The adverse effects of nervousness, nausea, and agitation are most closely associated with which substance?
A) Ephedrine
B) Phenylpropanolamine
C) Terbutaline
D) Ractopamine
54. Which β2-agonist is used as a repartitioning agent in beef cattle and has a 48-hour preslaughter withdrawal period?
A) Clenbuterol
B) Albuterol
C) Ractopamine
D) Zilpaterol
55. Which adrenergic antagonist is indicated for reducing hypertonus at the urethral sphincter in dogs and cats?
A) Prazosin
B) Phenoxybenzamine
C) Isoxsuprine
D) Albuterol
56. What is the mechanism of action of Yohimbine?
a) Competitive β1-receptor antagonist
b) Competitive α1- and α2-receptor antagonist
c) Selective β1-receptor antagonist
d) Nonselective β-receptor antagonist
57. Which drug is primarily used to reverse the effects of α2-receptor agonists in monogastric animals?
a) Phentolamine
b) Atipamezole
c) Propranolol
d) Atenolol
58. What is the primary route of elimination for Tolazoline?
a) Excretion in feces
b) Metabolism in the liver
c) Excretion in urine
d) Distribution into tissues
59. Which drug has the shortest elimination half-life among the listed options?
a) Propranolol
b) Atenolol
c) Metoprolol
d) Esmolol
60. What is the primary therapeutic use of Phentolamine?
a) Treatment of hypertension in ruminants
b) Reversal of α2-receptor agonist effects
c) Control of high blood pressure from sympathomimetic amine overdose
d) Management of supraventricular tachyarrhythmias
61. Which drug is known for its effectiveness in all species but is deemed too expensive for use in food animals?
a) Tolazoline
b) Yohimbine
c) Atipamezole
d) Esmolol
62. What is the primary adverse effect of Yohimbine?
a) Diarrhea
b) Fluid retention
c) Tachycardia
d) Hypertension
63. What is the primary mechanism of action of Propranolol?
a) Competitive α1- and α2-receptor antagonist
b) Nonselective β-receptor antagonist
c) Selective β1-receptor antagonist
d) Competitive α2-receptor antagonist
64. Which drug has the highest systemic bioavailability due to a significant first-pass effect?
a) Metoprolol
b) Propranolol
c) Atenolol
d) Esmolol
What is the primary pharmacokinetic difference between Atenolol and Metoprolol?
a) Atenolol has a longer half-life than Metoprolol.
b) Metoprolol has higher lipid solubility than Atenolol.
c) Atenolol undergoes significant first-pass metabolism.
d) Metoprolol is excreted primarily unchanged in the urine.
65. Which β-adrenergic antagonist is contraindicated in animals with asthma or bronchospasm?
a) Propranolol
b) Atenolol
c) Metoprolol
d) Esmolol
66. Which drug is preferred for the oral treatment of supraventricular arrhythmias in cats?
a) Propranolol
b) Atenolol
c) Metoprolol
d) Esmolol
67. What is the primary pharmacokinetic difference between Atenolol and Propranolol?
a) Atenolol has a shorter half-life than Propranolol.
b) Propranolol undergoes extensive hepatic metabolism.
c) Atenolol has higher protein binding characteristics.
d) Propranolol has lower lipid solubility than Atenolol.
68. Which β-adrenergic antagonist is often chosen over Propranolol in animals with bronchospastic disease?
a) Atenolol
b) Metoprolol
c) Esmolol
d) Sotalol
69. What is the primary therapeutic use of Sotalol in cats?
a) Treatment of hypertension
b) Management of thyrotoxicosis
c) Treatment of bronchospasm
d) Treatment of supraventricular tachyarrhythmias
70. Which class of antiarrhythmic drug is Sotalol classified as?
a) Class I
b) Class II
c) Class III
d) Class IV
71. How does food affect the bioavailability of Sotalol?
a) Increases it by 20%
b) Decreases it by 20%
c) Does not affect it
d) Increases it by 10%
72. What is the primary route of elimination for Sotalol?
a) Liver metabolism
b) Exhalation
c) Renal excretion
d) Biliary excretion
73. Which receptor does Acetylcholine primarily stimulate?
a) Alpha-adrenergic
b) Beta-adrenergic
c) Muscarinic
d) Nicotinic
74. What is the primary therapeutic use of Acetylcholine?
a) Treatment of ventricular tachycardias
b) Topical pupil constriction
c) GI motility enhancement
d) Lowering intraocular pressure
75. Which drug is used to antagonize the effects of Acetylcholine at muscarinic receptors?
a) Propranolol
b) Atropine
c) Neostigmine
d) Sotalol
76. What is the mechanism of action of Carbachol?
a) Inhibition of AChE
b) Carbamylation of AChE
c) Phosphorylation of AChE
d) Direct activation of muscarinic receptors
77. Which cholinergic agonist has a longer duration of action, similar to Neostigmine?
a) Edrophonium
b) Physostigmine
c) Pilocarpine
d) Pyridostigmine
78. What is the primary therapeutic use of Pilocarpine?
a) Treatment of glaucoma
b) Treatment of urinary bladder atony
c) Induction of miosis
d) Management of myasthenia gravis
79. How do anticholinesterase agents primarily act?
a) By blocking muscarinic receptors
b) By inhibiting acetylcholine synthesis
c) By preventing the breakdown of acetylcholine
d) By enhancing the release of acetylcholine
80. Which adverse effect is NOT associated with anticholinesterase agents?
a) Miosis
b) Bradycardia
c) Hypertension
d) Increased salivation
81. Which anticholinesterase agent is used topically in the treatment of open-angle glaucoma?
a) Physostigmine
b) Neostigmine
c) Echothiophate
d) Edrophonium
82. Which condition is NOT treated with Neostigmine?
a) Reversal of tubocurarine-like blockade
b) Paralytic ileus
c) Atony of the urinary bladder
d) Treatment of glaucoma
83. Which adverse effect is characteristic of organophosphate poisoning?
a) Tachycardia
b) Hypotension
c) SLUDD syndrome
d) Peripheral neuropathy
84. What is the primary treatment for dermal exposure to organophosphates?
a) Intravenous fluids
b) Oxygen therapy
c) Gastric lavage
d) Washing with soap and water
85. Which drug is a synthetic quaternary ammonium antimuscarinic agent primarily used to reduce colonic peristalsis in horses?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
86. A veterinarian administers a drug to a horse to control hyersalivation. Which drug could provide this therapeutic effect?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
87. Which drug is commonly used in veterinary ophthalmology to induce mydriasis and cycloplegia with a shorter duration of action compared to atropine?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
88. A dog presents with acute abdominal visceral spasm, pylorospasm, and associated symptoms. Which drug would be most effective in reducing colonic contractions with minimal mydriatic and salivary effects?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Aminopentamide
89. A veterinarian wants to administer a drug to a cat to control hyersalivation. Which drug can be administered subcutaneously for this purpose?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
90. Which drug, when combined with opioids, can be used to treat renal and biliary colic?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
91. A horse requires a drug to relax the rectum for easier rectal examination. Which drug is commonly administered intravenously for this purpose?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
92. Which drug is a synthetic quaternary ammonium used as a preanesthetic agent to reduce salivary and respiratory secretions?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
93. A veterinarian needs a drug with a shorter duration of action for inducing mydriasis and cycloplegia in a dog. Which drug should be preferred?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
94. A horse is experiencing hyperreflexic detrusor or urge urinary incontinence. Which drug can be used orally in its treatment?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
95. Which drug is used as an antispasmodic and antimuscarinic drug to treat colic and intestinal impaction in horses when administered intravenously?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
96. A veterinarian wants to administer a drug to control motion sickness in a horse orally. Which drug would be suitable for this purpose?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Scopolamine
97. Which drug is commonly used as a preanesthetic drug by parenteral administration and can be administered intravenously or intramuscularly to treat sinus bradycardia?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
98. A veterinarian wants to administer a drug to control hyersalivation in a cat. Which route of administration would be most appropriate for glycopyrrolate?
a) Intravenous
b) Intramuscular
c) Subcutaneous
d) Oral
99. Which drug, when administered intravenously, can be used to treat renal and biliary colic?
a) Atropine sulfate
b) Propantheline
c) Glycopyrrolate
d) Tropicamide
100. Which neuromuscular blocking drug is metabolized by a unique mechanism involving Hoffman elimination and ester hydrolysis?
a) Tubocurarine
b) Pancuronium
c) Atracurium
d) Vecuronium
101. Which animal species may experience prolonged paralysis after administration of Succinylcholine (SuCh) due to lower levels of pseudocholinesterase?
a) Dogs
b) Horses
c) Cats
d) Ruminants
102. What is the major route of elimination for Pancuronium?
a) Urine
b) Bile
c) Liver metabolism
d) Kidney
103. Which neuromuscular blocking drug may cause histamine release, resulting in bronchospasm and salivation, particularly in dogs and cats?
a) Tubocurarine
b) Pancuronium
c) Atracurium
d) Vecuronium
104. Which factor can prolong the duration of action of Succinylcholine (SuCh)?
a) Hepatic disease
b) Genetic mutations
c) Concomitant administration with aminoglycoside antibiotics
d) Inhalant anesthetics
Autacoids and their Pharmacological Modulators
1. A 3-year-old dog presents with acute onset vomiting. The owner reports feeding scraps of food from the table, including chicken. On examination, the dog appears uncomfortable and restless. Which of the following substances, if released due to ingestion of chicken, is primarily responsible for stimulating gastric acid secretion in this dog?
A) Serotonin
B) Bradykinin
C) Histamine
D) Leukotrienes
2. A 6-year-old cat is brought to the clinic with signs of respiratory distress. The owner reports that the cat has a history of allergic reactions to insect bites. Upon examination, the cat exhibits wheezing and labored breathing. Which receptor subtype is primarily responsible for the contraction of respiratory smooth muscle in this cat during an allergic reaction?
A) H1-receptors
B) H2-receptors
C) H3-receptors
D) H4-receptors
3. A 5-year-old horse is presented with a severe case of anaphylactic shock after being stung by a swarm of bees. Which of the following substances released during the allergic reaction is primarily responsible for mediating the vasodilation observed in the horse’s systemic circulation?
A) Prostaglandin D2
B) Leukotriene B4
C) Histamine
D) Platelet activating factor
4. A 7-year-old dog presents with a swollen abdomen and signs of discomfort. The owner reports that the dog accidentally ingested a plant while playing in the garden. Upon examination, the veterinarian suspects an allergic reaction. Which of the following receptors is primarily involved in the mediation of histamine-induced mast cell chemotaxis and leukotriene B4 production?
A) H1-receptors
B) H2-receptors
C) H3-receptors
D) H4-receptors
5. A 4-year-old rabbit is brought to the clinic with severe itching and skin redness after being stung by a wasp. The veterinarian suspects histamine release as the cause of these symptoms. Which of the following cell types primarily stores histamine in rabbits?
A) Basophils
B) Eosinophils
C) Mast cells
D) Neurons
6. A 2-year-old goat is brought to the clinic with signs of gastric distress after ingesting a toxic plant. The veterinarian suspects that the plant contains substances capable of releasing histamine. Which of the following pathways primarily contributes to the degradation of histamine in the goat’s body?
A) Conversion to 1-methylhistamine by imidazole-N-methyltransferase
B) Breakdown by diamine oxidase to form imidazoleacetic acid
C) Conversion to histidine by histamine decarboxylase
D) Breakdown by histaminase to form 1-methylhistamine
7. A 5-year-old pig is brought to the clinic with symptoms of respiratory distress after exposure to smoke from a fire. The veterinarian suspects histamine release due to physical injury. Which of the following stimuli can disrupt mast cells and lead to the release of histamine?
A) Cold
B) Heat
C) Trauma
D) All of the above
8. An 8-year-old dog is brought to the clinic with severe itching and skin redness after being stung by a bee. The veterinarian suspects histamine release as the cause of these symptoms. Which of the following receptor types primarily mediates the contraction of bronchiolar smooth muscle in dogs?
A) H1-receptors
B) H2-receptors
C) H3-receptors
D) H4-receptors
9. A 6-year-old cat is brought to the clinic with symptoms of anaphylactic shock after being stung by a hornet. The veterinarian suspects histamine release as a contributing factor. Which of the following physiological functions is primarily regulated by histamine in cats?
A) Gastric acid secretion
B) Bronchodilation
C) Vasodilation
D) Glandular secretion
10. A 4-year-old horse presents with signs of respiratory distress after being exposed to pollen. The owner reports a history of allergic reactions in the horse. Which of the following receptor types primarily mediates the relaxation of vascular smooth muscle in horses exposed to allergens?
A) H1-receptors
B) H2-receptors
C) H3-receptors
D) H4-receptors
11. A 3-year-old dog presents with acute abdominal pain and vomiting. The owner reports feeding the dog a meal containing spoiled meat. The veterinarian suspects histamine release due to bacterial action. Which of the following organs is primarily affected by histamine released from the digesta in the gastrointestinal tract?
A) Liver
B) Pancreas
C) Stomach
D) Small intestine
12. A 7-year-old cat is brought to the clinic with symptoms of anaphylactic shock after ingesting a toxic plant. The veterinarian suspects histamine release as the cause of these symptoms. Which of the following substances, if released during an allergic reaction, primarily mediates the increase in capillary permeability?
A) Prostaglandin D2
B) Leukotriene B4
C) Histamine
D) Platelet activating factor
13. A 5-year-old rabbit is presented with acute abdominal pain and vomiting. The owner reports that the rabbit accidentally ingested a plant known to induce allergic reactions. Upon examination, the veterinarian suspects histamine release as the cause of gastric distress. Which of the following tissues primarily stores histamine in rabbits?
A) Basophils
B) Eosinophils
C) Mast cells
D) Neurons
14. A 2-year-old goat is brought to the clinic with symptoms of anaphylactic shock after being stung by a wasp. The veterinarian suspects histamine release as a contributing factor. Which of the following receptor types primarily mediates the inhibition of histamine and other neurotransmitter release?
A) H1-receptors
B) H2-receptors
C) H3-receptors
D) H4-receptors
15. Which receptor activation enhances gastric acid secretion by ACh and gastrin on parietal cells?
A) H1-receptors
B) H2-receptors
C) M3-receptors
D) CCK2 receptors
16. What is the mechanism by which H2-antihistamines inhibit gastric acid secretion?
A) By increasing intracellular cAMP
B) By activating PKA
C) By competitively inhibiting histamine at H2-receptors
D) By activating calmodulin kinase
17. Which of the following is a therapeutic use of H1-antihistamines?
A) Treatment of peptic ulcers
B) Prevention of motion sickness
C) Induction of sedation
D) Inhibition of gastric acid secretion
18. Which type of H1-antihistamines is ionized at physiological pH and is difficult to cross the blood-brain barrier?
A) First-generation
B) Second-generation
C) Third-generation
D) Fourth-generation
19. Histamine-induced relaxation of contracted bronchiolar smooth muscle is a pharmacologic effect of which type of antihistamines?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
20. Which antihistamine class is primarily used for inhibition of gastric acid secretion?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
21. Which H2-antihistamine is reported to be the least potent among the four?
A) Ranitidine
B) Cimetidine
C) Famotidine
D) Nizatidine
22. Which of the following is a pharmacologic effect of H1-antihistamines?
A) Stimulation of sensory nerves
B) Decrease in capillary permeability
C) Inhibition of gastric acid secretion
D) Sedation induction
23. What is the primary route of excretion for cimetidine, ranitidine, and famotidine?
A) Liver
B) Kidneys
C) Feces
D) Lungs
24. Which antihistamine class contains drugs with an imidazole ring and uncharged side chains?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
25. Which antihistamine class has drugs that are primarily excreted by the kidneys as metabolites?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
26. What is the primary mechanism of action of H1-antihistamines?
A) Competitive antagonism of histamine receptors
B) Inhibition of calmodulin kinase
C) Activation of PKA
D) Inverse agonism at histamine receptors
27. Which antihistamine class is most commonly associated with CNS depression as a side effect?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
28. Which H2-antihistamine has the highest bioavailability?
A) Cimetidine
B) Ranitidine
C) Famotidine
D) Nizatidine
29. What is the primary therapeutic use of first-generation H1-antihistamines?
A) Treatment of gastric ulcers
B) Prevention of motion sickness
C) Sedation induction
D) Inhibition of bronchial smooth muscle contraction
30. Which antihistamine class has drugs that are primarily metabolized by cytochrome P450 enzymes?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
31. Which antihistamine class is associated with the risk of gynecomastia and decreased libido in humans?
A) H1-antihistamines
B) H2-antihistamines
C) H3-antihistamines
D) H4-antihistamines
32. Which antihistamine class has drugs that are difficult to cross the blood-brain barrier?
A) First-generation H1-antihistamines
B) Second-generation H1-antihistamines
C) Third-generation H1-antihistamines
D) Fourth-generation H1-antihistamines
33. Which H2-antihistamine has the longest plasma half-life in humans?
A) Cimetidine
B) Ranitidine
C) Famotidine
D) Nizatidine
34. What is the mechanism of action of H2-antihistamines?
A) Activation of calmodulin kinase
B) Inhibition of PKA
C) Competitive inhibition of histamine at H2-receptors
D) Activation of histamine receptors
35. Which drug primarily inhibits the release of histamine and other autacoids from mast cells without directly inhibiting H1 and H2 receptors?
a) Cromolyn sodium
b) Epinephrine
c) Phenylephrine
d) Cyproheptadine
36. What is the primary therapeutic use of cromolyn sodium?
a) Treatment of gastrointestinal disorders
b) Management of hypertension
c) Control of pulmonary and nasal allergic reactions
d) Relief of pain and inflammation
37. How is cromolyn sodium typically administered for clinical use?
a) Orally
b) Intravenously
c) Nebulized and delivered via a face mask
d) Subcutaneously
38. Which drug is primarily used to treat postpartum hemorrhage and induce uterine involution in obstetrics?
a) Cisapride
b) Metoclopramide
c) Ergonovine
d) Ketanserin
39. What is the primary mechanism of action of cisapride?
a) Gi/o-coupled D2-receptor antagonist
b) Agonist for Gs-coupled 5-HT4 receptor
c) 5-HT2 antagonist
d) Gq-coupled 5-HT2 receptor antagonist
40. Which drug is useful as an appetite stimulant in cats and for managing photic head shaking in horses?
a) Cisapride
b) Cyproheptadine
c) Ketanserin
d) Ergonovine
41. What is the primary adverse effect associated with metoclopramide administration in dogs and cats?
a) Diarrhea and colic
b) Sedation and anticholinergic activity
c) Changes in mental state and behavior
d) Nausea and vomiting
42. Which receptor subtype does ketanserin primarily antagonize?
a) 5-HT4
b) Gs-coupled
c) 5-HT2
d) Gi/o-coupled
43. What is the primary therapeutic use of ketanserin?
a) Appetite stimulation
b) Reduction of intraocular pressure in glaucoma
c) Treatment of postpartum hemorrhage
d) Relief of pain and inflammation
44. Which class of drugs antagonizes the physiological actions of histamine by sympathomimetic activity?
a) H1-antihistamines
b) H2-antihistamines
c) Serotonin agonists
d) Sympathomimetic drugs
45. What is the primary source of arachidonic acid for eicosanoid synthesis?
a) Membrane phospholipids
b) Adipose tissue
c) Platelets
d) Serum lipoproteins
46. Which enzyme is primarily responsible for releasing arachidonic acid from membrane phospholipids?
a) Phospholipase A2
b) Cyclooxygenase
c) Lipoxygenase
d) Lipoprotein lipase
47. Which pathway of arachidonic acid metabolism leads to the synthesis of prostaglandins, thromboxanes, and prostacyclin?
a) Cyclooxygenase pathway
b) 5-lipoxygenase pathway
c) 15-lipoxygenase pathway
d) Lipoprotein lipase pathway
48. What is the primary function of eicosanoids in the body?
a) Regulation of gut motility
b) Control of body temperature
c) Inflammatory response modulation
d) Regulation of sleep patterns
49. Which of the following fatty acids can lead to the synthesis of prostaglandin E1?
a) Dihomo-γ-linolenic acid (20:3)
b) Arachidonic acid (20:4)
c) Eicosapentaenoic acid (20:5)
d) Palmitic acid (16:0)
50. What is the significance of the subscript numbers in prostaglandin nomenclature?
a) Denote the number of carbon atoms in the aliphatic side chains
b) Denote the number of double bonds in the aliphatic side chains
c) Indicate the configuration of the hydroxyl group at carbon 9
d) Indicate the presence of a specific functional group on the cyclopentane ring
51. What is the primary pharmacological effect of ergot alkaloids?
a) Relaxation of smooth muscles
b) Stimulation of central nervous system
c) Constriction of blood vessels
d) Inhibition of platelet aggregation
52. Which of the following symptoms is NOT associated with ergotism in cattle?
a) Nervousness or convulsions
b) Gangrene of extremities
c) Increased birth weight
d) Agalactia
53. What is the major toxicant associated with fescue grass toxicosis in cattle?
a) Ketanserin
b) Cyproheptadine
c) Ergovaline
d) Cromolyn sodium
54. Which prostaglandin acts as a physiological antagonist of thromboxane A2?
a) PGE1
b) PGF2α
c) PGI2
d) TXA2
54. What is the primary function of thromboxane A2 in the cardiovascular system?
a) Vasodilation
b) Platelet aggregation
c) Smooth muscle relaxation
d) Endothelial cell damage
55. Which prostaglandin is commonly referred to as prostacyclin?
a) PGE1
b) PGE2
c) PGF2α
d) PGI2
56. Which receptor type does thromboxane A2 primarily signal through?
a) Gs-coupled receptor
b) Gq-coupled receptor
c) Gi-coupled receptor
d) G12/13-coupled receptor
57. What is the therapeutic use of misoprostol in veterinary medicine?
a) Inducing luteolysis
b) Preventing thromboxane A2 formation
c) Treating gastric ulceration caused by NSAIDs
d) Improving pulmonary function in asthma
58. Which prostaglandin is involved in the contraction of longitudinal muscle in the gut?
a) PGE2
b) PGF2α
c) PGI2
d) TXA2
59. Which leukotriene is a potent chemotactic chemical for leukocytes and promotes their adhesion to vascular endothelium?
a) LTB4
b) LTC4
c) LTD4
d) LTE4
60. What is the primary pharmacologic effect of cysteinyl leukotrienes in asthma?
a) Vasodilation
b) Mucous secretion inhibition
c) Bronchospasm
d) Smooth muscle relaxation
61. Which enzyme is responsible for the synthesis of leukotrienes from arachidonic acid?
a) Cyclooxygenase
b) Lipoxygenase
c) Phospholipase A2
d) Glutathione s-transferase
62. What is the primary adverse effect associated with zileuton, a leukotriene synthesis inhibitor?
a) GI distress
b) Liver toxicity
c) Hallucinations
d) Agranulocytosis
63. Which receptor type does platelet-activating factor primarily signal through?
a) Gs-coupled receptor
b) Gq-coupled receptor
c) Gi-coupled receptor
d) G12/13-coupled receptor
64. What is the primary effect of platelet-activating factor on blood pressure?
a) Vasodilation
b) Vasoconstriction
c) Platelet aggregation
d) Smooth muscle relaxation
65. Which leukotriene is known as the slow-reacting substance of anaphylaxis?
a) LTB4
b) LTC4
c) LTD4
d) LTE4
66. Which prostaglandin is synthesized by vascular endothelial cells and acts as a physiological antagonist of thromboxane A2?
a) PGE1
b) PGE2
c) PGF2α
d) PGI2
67. Which leukotriene is responsible for increasing capillary permeability?
a) LTB4
b) LTC4
c) LTD4
d) LTE4
68. Which enzyme is responsible for the synthesis of leukotrienes from arachidonic acid in human leukocytes?
a) 5-lipoxygenase
b) Cyclooxygenase
c) Phospholipase A2
d) Glutathione s-transferase
69. Which prostaglandin is used therapeutically to induce luteolysis and terminate pregnancy in veterinary medicine?
a) PGE1
b) PGE2
c) PGF2α
d) PGI2
70. What is the primary pharmacologic effect of thromboxane A2 in the cardiovascular system?
a) Vasodilation
b) Vasoconstriction
c) Platelet aggregation
d) Smooth muscle relaxation
71. Which prostaglandin receptor primarily signals through Gs-coupled receptors?
a) PGE1
b) PGE2
c) PGF2α
d) PGI2
72. Which leukotriene is known for its potent chemotactic effect on leukocytes?
a) LTB4
b) LTC4
c) LTD4
d) LTE4
73. What is a pathophysiological role of PAF?
a. Inhibition of platelet aggregation
b. Promotion of smooth muscle relaxation in the GI tract
c. Induction of ovulation
d. Promotion of inflammation and allergic responses
74. Which enzyme is responsible for metabolizing angiotensinogen to form angiotensin I?
a. Renin
b. Angiotensin-converting enzyme (ACE)
c. Angiotensin receptor kinase
d. Aldosterone synthase
75. What is the primary pharmacologic effect of angiotensin II?
a. Vasodilation
b. Decreased aldosterone secretion
c. Increased fluid retention
d. Blood pressure regulation
76. How do ACE inhibitors exert their pharmacologic effects?
a. By blocking angiotensin II receptors
b. By promoting the synthesis of aldosterone
c. By inhibiting the conversion of angiotensin I to angiotensin II
d. By increasing renin secretion
77. Which receptors mediate most of the actions of angiotensin II?
a. AT1 receptors
b. AT2 receptors
c. BK1 receptors
d. BK2 receptors
78. What is the primary pharmacologic effect of bradykinin and kallidin?
a. Vasoconstriction
b. Smooth muscle relaxation
c. Increased aldosterone secretion
d. Platelet aggregation
79. What is the precursor for the synthesis of bradykinin and kallidin?
a. Angiotensinogen
b. Renin
c. Kallikreins
d. ACE
80. Which enzyme inactivates both bradykinin and kallidin?
a. Angiotensin-converting enzyme (ACE)
b. Renin
c. Aldosterone synthase
d. Prostacyclin synthase
81. What is the mechanism of action of bradykinin?
a. Acts on AT1 receptors
b. Acts on BK1 and BK2 receptors
c. Stimulates NO synthesis
d. Stimulates aldosterone secretion
82. Which of the following is a therapeutic use of angiotensin II?
a. Management of acute pancreatitis
b. Treatment of hypertension
c. Relief of allergic responses
d. Prevention of platelet aggregation
83. What effect does angiotensin II have on aldosterone secretion?
a. Decreases it
b. Increases it
c. Has no effect
d. Converts it to angiotensin I
84. Which receptors mediate the inhibitory effects of angiotensin II?
a. AT1 receptors
b. AT2 receptors
c. BK1 receptors
d. BK2 receptors
85. What is the primary pharmacologic effect of kinins on blood vessels?
a. Vasoconstriction
b. Vasodilation
c. Platelet aggregation
d. Smooth muscle contraction
86. What role do kinins play in increasing vascular permeability?
a. They decrease permeability
b. They have no effect on permeability
c. They increase permeability
d. They stimulate platelet aggregation
Drugs Acting on the Central Nervous System
- Which neurotransmitter is NOT typically found in the central nervous system (CNS)?
A) Dopamine
B) γ-Aminobutyric acid (GABA)
C) Acetylcholine (ACh)
D) Insulin
Answer: d
2. Which property does NOT facilitate the crossing of the blood-brain barrier (BBB) by a drug?
A) Lipid solubility
B) Large molecular size
C) Poor protein binding
D) Nonionized state at cerebrospinal fluid (CSF) pH
3. What is the primary mechanism by which anticonvulsant drugs stabilize neuronal membranes?
A) Decreasing neurotransmitter release
B) Activating GABA-gated Cl− channels
C) Blocking dopamine receptors
D) Inhibiting acetylcholine synthesis
4. Which of the following is a common adverse effect of phenobarbital in dogs?
A) Hyperactivity
B) Hepatotoxicity
C) Hypothermia
D) Increased seizure frequency
5. Phenobarbital is classified as which type of barbiturate?
A) Thiobarbiturate
B) Methylbarbiturate
C) Oxybarbiturate
D) Deoxybarbiturate
6. What is a major consideration for administering anticonvulsant drugs in veterinary medicine?
A) They should be water-soluble.
B) They should have a short half-life.
C) They should achieve steady plasma levels over time.
D) They should be administered only intravenously.
7. Which drug is known to increase cytochrome P450 enzyme activity in the liver, potentially leading to altered metabolism of other drugs?
A) Chloramphenicol
B) Phenobarbital
C) Pyrantel
D) Metoclopramide
8. For long-term control of seizures in dogs, which drug is most commonly used?
A) Primidone
B) Pentobarbital
C) Phenobarbital
D) Metoclopramide
9. What should be regularly monitored in dogs receiving chronic phenobarbital therapy to detect hepatotoxicity?
A) Blood pressure
B) Serum glucose levels
C) Serum enzyme concentrations
D) Heart rate
10. Which anticonvulsant drug is rarely used in cats due to its slow metabolism and long half-life in this species?
A) Phenobarbital
B) Primidone
C) Pentobarbital
D) Metoclopramide
11. What is a significant risk when pentobarbital is used to control status epilepticus?
A) Renal failure
B) Hyperthermia
C) Cardiopulmonary depression
D) Hypertension
12. Which mechanism is NOT a way through which neurotransmitter-receptor complexes can alter neuronal membrane potential?
A) Directly altering cell membrane permeability
B) Activating second messengers
C) Inhibiting neurotransmitter reuptake
D) Opening specific ion channels
13. Which drug may lower the seizure threshold, thereby potentially precipitating seizures in an otherwise well-controlled patient?
A) Pyrantel
B) Levamisole
C) Acepromazine
D) All of the above
14. What is the elimination half-life of phenobarbital in dogs?
A) 8–12 hours
B) 13–18 hours
C) 32–90 hours
D) Over 100 hours
15. Which clinical sign is an indication of possible liver toxicity in dogs on phenobarbital therapy?
A) Decreasing serum albumin concentrations
B) Increased polydipsia
C) Increased polyuria
D) Hyperactivity
16. What is the primary mechanism by which phenytoin stabilizes neuronal membranes to limit seizure activity?
A. Enhancing GABA activity
B. Reducing Na+ influx during the action potential
C. Inhibiting Ca2+ influx during depolarization
D. Promoting K+ efflux
17. Which of the following correctly describes phenytoin’s effect on potassium (K+) movement during the action potential?
A. Promotes K+ influx into the cell
B. Delays K+ movement out of the cell, increasing the refractory period
C. Has no effect on K+ movement
D. Decreases the refractory period by enhancing K+ efflux
18. Why is phenytoin use considered impractical for dogs?
A. Low oral absorption rate
B. High potential for toxicity
C. Short half-life in dogs
D. Ineffective in controlling seizures
19. For what secondary condition, aside from seizures, has phenytoin been recommended in dogs?
A. Pain management
B. Anxiety
C. Digitalis-induced ventricular arrhythmias
D. Hypertension
20. What is the half-life range of phenytoin in cats?
A. 3–7 hours
B. 8 hours
C. 42–108 hours
D. 25–50 hours
21. Which benzodiazepine is commonly used as a maintenance anticonvulsant in cats but not in dogs due to rapid tolerance development?
A. Diazepam
B. Lorazepam
C. Midazolam
D. Clonazepam
22. What is the primary mechanism of action of benzodiazepines in the treatment of seizures?
A. Inhibiting sodium channels
B. Activating GABA-gated Cl− channels
C. Blocking NMDA receptors
D. Enhancing calcium influx
23. Which adverse effect is associated with the oral administration of diazepam in cats?
A. Respiratory depression
B. Acute fatal hepatic necrosis
C. Severe asthma
D. Increased seizure frequency
24. Midazolam is considered more potent than diazepam for anticonvulsant effects, but what is the key difference in its pharmacokinetics?
A. Longer duration of action
B. Shorter duration of action
C. More severe side effects
D. Lower potency
25. Why is lorazepam a safer option for use in geriatric dogs or those with compromised liver function compared to other benzodiazepines?
A. It has a longer half-life
B. It does not produce active metabolites
C. It is metabolized entirely by the kidneys
D. It enhances hepatic enzyme induction
26. Which drug is not recommended for use in cats due to its potential to cause severe asthma?
A. Diazepam
B. Phenytoin
C. Potassium bromide (KBr)
D. Valproic acid
27. What is the primary therapeutic use of potassium bromide (KBr) in veterinary medicine?
A. Pain management in cats
B. Treating refractory seizures in dogs
C. Sedation in horses
D. Anti-inflammatory in dogs
28. Which adverse effect is commonly associated with the initial phase of potassium bromide therapy in dogs?
A. Severe asthma
B. Acute hepatic necrosis
C. Transient sedation
D. Rapid tolerance development
29. How does valproic acid primarily exert its effect in the treatment of seizures?
A. Inhibiting Na+ influx
B. Enhancing GABA activity
C. Blocking NMDA receptors
D. No clear mechanism described
30. Which drug is rapidly converted to its active form in the acidic environment of the stomach?
A. Diazepam
B. Phenytoin
C. Sodium valproate
D. Potassium bromide
31. Why is valproic acid considered impractical for long-term use in dogs?
A. Poor absorption from t31. he GI tract
B. Short half-life
C. High potential for liver toxicity
D. Rapid development of tolerance
32. Which benzodiazepine is highly lipid-soluble and rapidly crosses the blood-brain barrier after administration?
A. Diazepam
B. Lorazepam
C. Midazolam
D. Clonazepam
33. What is the pharmacologically active metabolite of diazepam?
A. Temazepam
B. Lorazepam
C. α-Hydroxymidazolam
D. Desmethyldiazepam (nordiazepam)
34. Which of the following drugs is known for causing behavioral changes such as irritability and depression in some animals?
A. Diazepam
B. Phenytoin
C. Potassium bromide
D. Valproic acid
35. Which drug’s metabolites are primarily excreted through the kidneys without undergoing any significant metabolic change?
A. Diazepam
B. Potassium bromide
C. Phenytoin
D. Valproic acid
36. A 5-year-old dog presents with refractory seizures and is started on gabapentin. Which mechanism primarily contributes to its anticonvulsant effect?
a. Increasing GABA content in neurons
b. Inhibiting voltage-dependent Ca2+ channels
c. Blocking NMDA receptors
d. Inhibiting voltage-dependent Na+ channels
37. A 3-year-old cat is experiencing chronic pain and is prescribed gabapentin. What is a common adverse effect that might be observed in this patient?
a. Vomiting
b. Sedation
c. Liver failure
d. Hypotension
38. A dog is treated with levetiracetam for refractory epilepsy. What is the proposed interaction of levetiracetam that contributes to its anticonvulsant effect?
a. Inhibiting NMDA receptors
b. Binding to synaptic vesicle protein
c. Increasing GABA content
d. Blocking voltage-dependent Na+ channels
39. A 7-year-old dog is prescribed felbamate for epilepsy. Which notable adverse effect necessitates periodic serum biochemistry monitoring?
a. Bone marrow depression
b. Liver dysfunction
c. Anemia
d. Polyphagia
40. A 4-year-old dog with refractory epilepsy is being treated with zonisamide. What is the elimination half-life of this drug in dogs?
a. 3–4 hours
b. 5–6 hours
c. 8 hours
d. 15 hours
41. A dog with hepatotoxicity is on felbamate therapy. What is the percentage of felbamate excreted unchanged in the urine?
a. 30%
b. 50%
c. 70%
d. 90%
42. An adult dog undergoes surgery and receives doxapram postoperatively. What is the primary therapeutic use of doxapram in this context?
a. To manage pain
b. To stimulate respiration
c. To prevent seizures
d. To induce sedation
43. A neonate is administered doxapram after assisted birth. What is a key limitation of doxapram in neonates?
a. It induces seizures
b. It causes hypotension
c. It is not effective in reviving severely depressed neonates
d. It causes respiratory depression
44. A dog undergoing anesthesia is administered a phenothiazine derivative. What is the primary mechanism of action of phenothiazines?
a. Blocking GABA receptors
b. Inhibiting NMDA receptors
c. Blocking dopamine, α1-adrenergic, and serotonergic receptors
d. Enhancing voltage-dependent Ca2+ channels
45. A veterinary student is studying the cardiovascular effects of phenothiazine tranquilizers. Which effect is commonly observed?
a. Increased heart rate
b. Hypotension
c. Hypertension
d. Increased myocardial contractility
46. An 8-year-old dog is on gabapentin therapy. Which adverse effect should be monitored due to abrupt discontinuation of the drug?
a. Ataxia
b. Sedation
c. Seizures
d. Vomiting
47. A dog with a brain tumor is treated with felbamate. Which of the following is NOT a mechanism of action of felbamate?
a. Blockade of NMDA receptors
b. Potentiation of GABA-mediated inhibition
c. Inhibition of voltage-dependent Na+ channels
d. Inhibition of voltage-dependent K+ channels
48. A dog treated with levetiracetam shows signs of drowsiness and vomiting. What is the most appropriate course of action?
a. Continue the medication and monitor the dog
b. Abruptly discontinue the medication
c. Increase the dosage
d. Substitute with another anticonvulsant immediately
49. A cat with refractory epilepsy is prescribed levetiracetam. What is the elimination half-life of levetiracetam in cats?
a. 2 hours
b. 4 hours
c. 6 hours
d. 8 hours
50. A dog is administered doxapram to evaluate laryngeal function. What is a potential adverse effect of high doses of doxapram?
a. Hypotension
b. Hyperventilation
c. Bradycardia
d. Hypoglycemia
51. A dog on zonisamide therapy presents with ataxia and anorexia. How should these side effects be interpreted?
a. Normal, as zonisamide has a high safety margin
b. Indicative of overdose, require immediate discontinuation
c. Signs of drug allergy, necessitating a switch to another medication
d. Symptoms of underlying liver disease
52. An adult dog receives phenothiazine for sedation. What effect does phenothiazine have on the respiratory system?
a. It enhances respiratory rate
b. It causes respiratory depression
c. It has no effect on respiration
d. It increases ventilatory response to CO2
53. A dog receives phenothiazine and exhibits hypotension. What is the primary cause of this hypotension?
a. Increased cardiac output
b. α1-adrenergic receptor blockade
c. β-adrenergic receptor activation
d. Increased sympathetic tone
54. A dog is administered doxapram intravenously. What is the typical duration of action for doxapram administered this way?
a. 2–3 minutes
b. 5–10 minutes
c. 15–20 minutes
d. 30–40 minutes
55. A dog undergoing phenothiazine therapy shows a decrease in packed cell volume. What is the most likely explanation for this observation?
a. Hemolysis
b. Splenic sequestration of red blood cells
c. Decreased erythropoiesis
d. Increased bleeding tendency
56. Which receptor activation by epinephrine leads to liver glycogenolysis in the context of phenothiazine-induced hyperglycemia?
a) α1-receptors
b) β1-receptors
c) β2-receptors
d) α2-receptors
57. Hyperprolactinemia caused by phenothiazines is primarily due to the blockade of which receptors?
a) H1-receptors
b) D2-receptors
c) α1-receptors
d) β2-receptors
58. Why should phenothiazines be used cautiously as a restraining agent in aggressive dogs?
a) They can cause liver damage.
b) They may make the animal more prone to startle and react to noises.
c) They can induce seizures.
d) They cause respiratory depression.
59. Which phenothiazine is used to control allergies due to its H1-receptor blocking properties?
a) Acepromazine
b) Trimeprazine
c) Chlorpromazine
d) Thioridazine
60. What is the primary metabolic pathway for phenothiazines in the liver?
a) Sulfation
b) Glucuronidation
c) Oxidation via cytochrome P450 enzymes
d) Acetylation
61. What is the recommended FARAD extralabel withdrawal interval for acepromazine in cattle preslaughter?
a) 24 hours
b) 48 hours
c) 4 days
d) 7 days
62. Which of the following is an adverse effect of accidental intracarotid administration of phenothiazines in horses?
a) Immediate seizure activity
b) Bradycardia
c) Hypotension
d) Hyperglycemia
63. Why should phenothiazines not be given to animals treated with organophosphate compounds within the past month?
a) They may cause liver toxicity.
b) They inhibit cholinesterase and may worsen clinical signs of anti-ChE poisoning.
c) They cause severe hypotension.
d) They induce respiratory depression.
64. What effect of phenothiazines makes them undesirable for sedation prior to allergy testing?
a) They cause hyperglycemia.
b) They block H1-receptors.
c) They induce hypotension.
d) They can cause seizures.
65. Which condition is a contraindication for the use of phenothiazines?
a) Liver dysfunction
b) Diabetes
c) Hyperthyroidism
d) Chronic kidney disease
66. Which benzodiazepine is used rectally or IV to control seizures and status epilepticus?
a) Midazolam
b) Zolazepam
c) Diazepam
d) Clonazepam
67. What is the mechanism by which benzodiazepines provide muscle relaxation?
a) Inhibition at the neuromuscular junction
b) Central inhibition in the spinal cord
c) Blockade of D2-receptors
d) Stimulation of α2-receptors
68. What is the main cardiovascular effect of benzodiazepines?
a) Severe hypotension
b) Hypertension
c) Minimal cardiovascular effects
d) Tachycardia
69. Which competitive antagonist is used to reverse the effects of benzodiazepines?
a) Yohimbine
b) Flumazenil
c) Atipamezole
d) Tolazoline
70. Which species is most sensitive to the sedative effects of α2-agonists?
a) Pigs
b) Horses
c) Dogs
d) Ruminants
71. What is the primary mechanism of action of α2-agonists in the CNS?
a) Activation of α1-receptors
b) Activation of Gi/o-coupled α2-receptors
c) Blockade of D2-receptors
d) Inhibition of β2-receptors
72. Which α2-agonist is known to cause the most potent sedation in clinical doses?
a) Xylazine
b) Medetomidine
c) Romifidine
d) Detomidine
73. What is the primary reason for α2-agonist-induced diuresis?
a) Increased renal blood flow
b) Inhibition of vasopressin release and action
c) Activation of α1-receptors in the kidneys
d) Increased aldosterone secretion
74. Why should xylazine not be used in animals with cardiac aberrations?
a) It induces severe bradycardia and sinus arrhythmia.
b) It causes significant hypertension.
c) It leads to hyperglycemia.
d) It can precipitate seizures.
75. Which α2-agonist is FDA-approved for use in deer and elk, among other animals?
a) Detomidine
b) Romifidine
c) Xylazine
d) Medetomidine
76. What adverse effect is commonly associated with the use of xylazine in ruminants?
a) Hypoxemia
b) Hypertension
c) Tachycardia
d) Seizures
77. What is the FARAD recommended milk withdrawal time for xylazine in cattle?
a) 12 hours
b) 24 hours
c) 48 hours
d) 72 hours
78. Which adverse effect of phenothiazines is due to relaxation of retractive penis muscles via α1-receptor blockade?
a) Seizures
b) Paraphimosis
c) Hyperglycemia
d) Hypotension
79. What should be avoided in the treatment of bradycardia induced by α2-agonists?
a) Atropine
b) Flumazenil
c) Yohimbine
d) Tolazoline
80. What is the elimination half-life of detomidine following intramuscular (IM) administration in horses?
a) 1.2 hours
b) 1.5 hours
c) 1.8 hours
d) 2.0 hours
81. Which metabolite is formed during the metabolism of detomidine in horses?
a) Detomidine carboxylic acid
b) Hydroxydetomidine sulfate
c) Hydroxydetomidine glucuronide
d) Detomidine sulfate
82. Which adverse effect is commonly seen in horses following the recommended dose of detomidine?
a) Severe muscle tremors
b) Partial penis prolapse
c) CNS excitation
d) Myocardial necrosis
83. What potentially fatal condition can occur if IV sulfonamides are used in detomidine-treated horses?
a) Severe hypotension
b) Dysrhythmias
c) Respiratory depression
d) Liver failure
84. What is the elimination half-life of medetomidine following intramuscular (IM) administration?
a) 30 minutes
b) 1.0-1.5 hours
c) 2 hours
d) 3-4 hours
85. What is a notable pharmacological characteristic of medetomidine?
a) It is metabolized by the kidney
b) It inhibits cytochrome P450 enzymes of the liver
c) It has a slow onset of action
d) It induces hyperexcitability
86. Which α2-antagonist may be used to reverse the adverse effects of medetomidine?
a) Atipamezole
b) Yohimbine
c) Naloxone
d) Flumazenil
87. What is the elimination half-life of romifidine following intravenous (IV) administration in horses?
a) 30 minutes
b) 50 minutes
c) 1 hour
d) 2 hours
88. Which receptor subtype is primarily responsible for the profound analgesia produced by opioid agonists?
a) Mu (μ) receptors
b) Kappa (κ) receptors
c) Delta (δ) receptors
d) Sigma (σ) receptors
89. Which receptor activation is associated with the inhibition of vasopressin release and diuresis?
a) Mu (μ) receptors
b) Kappa (κ) receptors
c) Delta (δ) receptors
d) Sigma (σ) receptors
90. Which opioid receptor subtype is located in the limbic system, cerebral cortex, and spinal cord, and its activation results in cardiovascular depression?
a) Mu (μ) receptors
b) Kappa (κ) receptors
c) Delta (δ) receptors
d) Sigma (σ) receptors
91. What is the mechanism of action of morphine?
a) Kappa-agonist and Delta-antagonist
b) Mu-agonist and less potent Kappa-agonist
c) Delta-agonist and Kappa-antagonist
d) Sigma-agonist and Mu-antagonist
92. Which adverse effect of morphine is mediated by both μ- and κ-receptors in dogs and primates?
a) Miosis
b) Mydriasis
c) Hyperexcitability
d) Constipation
93. What can be used to reverse the effects of morphine in newborns and dams?
a) Flumazenil
b) Atipamezole
c) Naloxone
d) Yohimbine
94. Why should opioids be used with caution in dogs with head injuries?
a) They cause severe hypotension
b) They induce hyperexcitability
c) They increase cerebral blood flow, potentially worsening hemorrhage and edema
d) They cause miosis, impairing vision
95. A 7-year-old dog is brought to the clinic with signs of moderate pain and a persistent cough. The vet decides to prescribe a medication that has both analgesic and antitussive properties and is given orally. Which drug is the vet most likely to prescribe?
a. Methadone
b. Tramadol
c. Fentanyl
d. Oxymorphone
96. A dog receives an oral dose of tramadol. Afterward, it is noted that the dog’s bioavailability of tramadol is around 65%, but there is significant inter-patient variability. What could be a reason for this variability?
a. Extensive first-pass metabolism
b. Different rates of absorption
c. Variation in liver enzyme activity
d. Differences in gastrointestinal motility
97. A 5-year-old canine is treated with tramadol for pain management. Which of the following is true regarding tramadol’s metabolism in dogs?
a. It is minimally metabolized in the liver
b. Its active metabolite, O-desmethyltramadol, is significantly less potent than tramadol
c. Tramadol is extensively metabolized in the liver, and O-desmethyltramadol is much more potent than tramadol
d. Naloxone completely antagonizes the analgesic effects of tramadol
98. In a veterinary setting, a dog is administered methadone as an alternative to morphine. Which characteristic of methadone makes it a preferable option for this animal?
a. Causes more sedation than morphine
b. Causes less sedation and vomiting than morphine
c. Has a longer elimination half-life than morphine
d. Is not metabolized in the liver
99. A cat is given oxymorphone as part of a preanesthetic regimen. The veterinary technician notes a significant decrease in cardiac output after IV administration. What other cardiovascular effects might be observed?
a. Decreased mean arterial pressure and systemic vascular resistance
b. Increased mean arterial pressure and systemic vascular resistance
c. Increased heart rate and decreased systemic vascular resistance
d. Decreased heart rate and decreased mean arterial pressure
100. A dog is being prepared for surgery and is administered oxymorphone as a preanesthetic. What is the expected onset of analgesic efficacy for this drug?
a. Immediately
b. Within 5 minutes
c. Within 15-30 minutes
d. Within an hour
101. Hydromorphone is chosen over oxymorphone for a canine patient due to cost considerations. What is a key difference between these two drugs?
a. Hydromorphone has a longer duration of action
b. Hydromorphone has a shorter duration of action
c. Hydromorphone is more expensive
d. Hydromorphone is less potent
102. A veterinary surgeon opts for fentanyl patches to control chronic pain in a postoperative dog. When can effective plasma concentrations be expected after topical application?
a. 1 hour
b. 7 hours
c. 24 hours
d. 48 hours
103. During a surgical procedure, a cat receives IV fentanyl. Why does fentanyl provide a more rapid onset of analgesia compared to morphine?
a. It is more lipid soluble
b. It is less lipid soluble
c. It is administered in higher doses
d. It is less metabolized by the liver
104. A dog is given alfentanil, a derivative of fentanyl, for analgesia. Which statement is true regarding its pharmacokinetics?
a. It is primarily excreted unchanged in the urine
b. It has a longer elimination half-life than fentanyl
c. It is four times more potent than fentanyl
d. It is rapidly absorbed following administration
105. A large wild animal, such as an elk, requires immobilization for medical examination. Which opioid would be most suitable for this purpose?
a. Tramadol
b. Methadone
c. Carfentanil
d. Sufentanil
106. A wild horse is immobilized with carfentanil and xylazine. What adverse effect might be observed in domestic horses that makes carfentanil use unacceptable for them?
a. Severe muscle rigidity and paddling
b. Hypotension and bradycardia
c. Sedation and decreased gut motility
d. Respiratory depression
107. Butorphanol is chosen to manage a dog’s chronic nonproductive cough. What is the mechanism behind its effectiveness as an antitussive?
a. It is a full agonist for μ-receptors
b. It is a full agonist for κ-receptors
c. It is a partial agonist for μ-receptors and full agonist for κ-receptors
d. It is an antagonist for μ-receptors
108. A horse receives butorphanol IV. How long after administration will the peak analgesic effect be observed?
a. 3 minutes
b. 15-30 minutes
c. 1 hour
d. 4 hours
109. Which adverse effect is common in dogs and cats treated with butorphanol?
a. Seizures and hyperthermia
b. Sedation and ataxia
c. Excitement and increased gut motility
d. Hyperactivity and increased appetite
110. A dog undergoing surgery is given nalbuphine, an opioid agonist-antagonist. Which receptors does nalbuphine primarily affect?
a. Antagonizes κ-receptors and activates μ-receptors
b. Antagonizes μ-receptors and activates κ-receptors
c. Partially agonizes both μ- and κ-receptors
d. Antagonizes both μ- and κ-receptors
111. A veterinarian is considering using methadone for analgesia in a dog. Which statement accurately describes methadone’s pharmacokinetics?
a. It is poorly distributed in the body
b. It has a short elimination half-life in dogs
c. It is extensively bound to albumin
d. It is not metabolized by cytochrome P450 enzymes
112. A dog is given sufentanil, which is noted to be significantly more potent than fentanyl. What is the elimination half-life of sufentanil in humans?
a. 20 minutes
b. 2.5 hours
c. 4 hours
d. 24 hours
113. A cat is administered buprenorphine, an opioid agonist-antagonist. What is buprenorphine’s receptor activity?
a. Full agonist for both μ- and κ-receptors
b. Partial agonist for μ-receptors and antagonist for κ-receptors
c. Antagonist for both μ- and κ-receptors
d. Full agonist for μ-receptors and antagonist for κ-receptors
114. A dog treated with butorphanol exhibits adverse effects such as ataxia and anorexia. Which of the following is another possible adverse effect of butorphanol in dogs and cats?
a. Hyperactivity
b. Increased appetite
c. Diarrhea
d. Increased gut motility
115. Which of the following is a primary advantage of agonist-antagonist opioids over pure μ-receptor agonists?
A) They completely eliminate respiratory depression.
B) They have a shorter duration of action.
C) They eliminate most respiratory depression without totally eliminating analgesia.
D) They are easier to reverse in cases of overdose.
116. What is the mechanism of action for Buprenorphine?
A) Full agonist at μ-receptor and antagonist at κ-receptor
B) Partial agonist at μ-receptor and antagonist at κ-receptor
C) Full agonist at both μ- and κ-receptors
D) Antagonist at both μ- and κ-receptors
117. What is a significant characteristic of Buprenorphine’s pharmacokinetics?
A) It is not bound to plasma proteins.
B) It is metabolized primarily by renal excretion.
C) It has a shorter duration of action compared to other opioids.
D) It has a longer elimination half-life in humans due to binding to globulins.
118. Which of the following is NOT a therapeutic use of Nalbuphine?
A) Control of mild to moderate pain in dogs and cats
B) Topical application for corneal ulcer pain
C) Long-term analgesic use in small animals
D) Injectable administration for moderate pain relief
119. Naloxone’s primary use is to:
A) Serve as a long-term analgesic
B) Reverse respiratory depression caused by μ-receptor opioids
C) Act as a sedative for postoperative recovery
D) Enhance the analgesic effects of opioids
120. What is the major adverse effect of Buprenorphine?
A) Hypotension
B) Respiratory depression and sedation
C) Hyperactivity
D) Gastrointestinal distress
121. What is the duration of action of Naloxone when administered IV or IM?
A) 1-2 minutes
B) 45-90 minutes
C) Up to 8 hours
D) 37 hours
122. Which opioid antagonist is relatively free of adverse effects in animals and is long-lasting?
A) Naloxone
B) Naltrexone
C) Buprenorphine
D) Nalbuphine
123. Which opioid has 30 times the analgesic potency of morphine and is resistant to antagonism by naloxone?
A) Nalbuphine
B) Buprenorphine
C) Naltrexone
D) Butorphanol
124. For which therapeutic purpose is Nalbuphine administered topically in a 1% solution?
A) Control of mild to moderate pain
B) Pain associated with corneal ulcer
C) Reversal of respiratory depression
D) Treatment of behavioral problems in dogs
Behavior-Modifying Drugs
1. A 5-year-old dog presents with signs of fear and anxiety during thunderstorms. Which class of drugs is suitable for managing this condition and why?
a) Phenothiazines, because they effectively calm aggressive behavior
b) Benzodiazepines, because they induce membrane hyperpolarization and have rapid onset
c) SSRIs, because they are the first choice for rapid relief of anxiety
d) Progestins, because they enhance monoaminergic neurotransmission
2. A cat is diagnosed with separation anxiety and inappropriate urination. Which benzodiazepine is appropriate for managing this condition?
a) Diazepam
b) Amitriptyline
c) Fluoxetine
d) Selegiline
3. An elderly dog shows signs of cognitive dysfunction. Which neurotransmitter imbalance is most likely involved?
a) Acetylcholine
b) Dopamine
c) Serotonin
d) Norepinephrine
4. Which of the following is a contraindication for using benzodiazepines in animals?
a) Anxiety
b) Aggression
c) Phobia
d) Separation anxiety
5. A dog with a history of storm phobia is being considered for treatment. Which drug would be contraindicated due to its potential to increase aggressive behavior?
a) Phenothiazines
b) Benzodiazepines
c) SSRIs
d) MAOIs
6. In the monoamine hypothesis of mood, what is the proposed consequence of impaired activity of monoamines?
a) Cognitive dysfunction
b) Increased aggression
c) Depression
d) Hyperactivity
7. A horse presents with extreme timidity. Which benzodiazepine property makes it useful in managing this condition?
a) Long half-life
b) Minimal CNS depressant effects
c) High protein binding
d) Rapid absorption from the GI tract
8. What is the primary neurotransmitter involved in the behavioral and drug reinforcement mechanisms within the brain?
a) Serotonin
b) Norepinephrine
c) Dopamine
d) Acetylcholine
9. A dog is diagnosed with compulsive disorder. Which class of drugs would be effective by enhancing serotonergic neurotransmission?
a) TCAs
b) MAOIs
c) SSRIs
d) Benzodiazepines
10. Which neurotransmitter is central to the regulation of sleep, body temperature, and higher cognitive functions?
a) Dopamine
b) Serotonin
c) Norepinephrine
d) Acetylcholine
11. A veterinary technician is instructed to monitor a dog for signs of paradoxical excitement. Which class of drugs might cause this adverse effect?
a) Progestins
b) MAOIs
c) Benzodiazepines
d) SSRIs
12. In the treatment of inappropriate elimination behavior in cats, which class of drugs can be used in combination with benzodiazepines for enhanced efficacy?
a) Progestins
b) TCAs
c) SSRIs
d) MAOIs
13. Which neurotransmitter’s cell bodies are located in the locus coeruleus and are involved in the regulation of anxiety and mood?
a) Dopamine
b) Norepinephrine
c) Serotonin
d) Acetylcholine
14. A cat is undergoing treatment with a tricyclic antidepressant. What side effect should be monitored due to its muscarinic blocking effects?
a) Increased aggression
b) Urine retention
c) Hypersalivation
d) Hyperactivity
15. A dog treated with fluoxetine shows improvement in behavior. What is the mechanism of action for this drug?
a) Inhibits monoamine oxidase-B
b) Increases synaptic levels of serotonin
c) Blocks muscarinic receptors
d) Facilitates GABA-mediated chloride conductance
16. Which of the following is NOT a therapeutic use of diazepam in cats?
a. Treatment of urine spraying behavior
b. Treatment of separation anxiety
c. Treatment of compulsive disorders
d. Treatment of fear-induced aggression
17. Which metabolite of diazepam has the longest half-life in cats?
a. Temazepam
b. Desmethyldiazepam (nordiazepam)
c. Oxazepam
d. Diazepam
18. What is the primary reason for choosing alprazolam over diazepam for treating storm phobia in dogs?
a. Alprazolam has fewer side effects.
b. Alprazolam is more effective.
c. Alprazolam has a faster onset of action.
d. Alprazolam is less likely to cause hepatic toxicosis.
19. In cats, what is a major adverse effect of diazepam?
a. Renal failure
b. Hepatic necrosis
c. Pancreatitis
d. Cardiomyopathy
20. Which benzodiazepine is primarily oxidized in the acidic environment of the stomach to its active metabolite before absorption?
a. Diazepam
b. Lorazepam
c. Clorazepate
d. Oxazepam
21. Buspirone exerts its anxiolytic effects primarily through partial agonism of which receptor?
a. GABA-A receptor
b. 5-HT1A receptor
c. Dopamine receptor
d. NMDA receptor
22. What is the plasma protein binding capacity of diazepam?
a. 80%
b. 85%
c. 95%
d. 98%
23. In which scenario is lorazepam considered a suitable alternative to diazepam in cats?
a. When the cat has renal dysfunction
b. When the cat has hepatic necrosis
c. When the cat has behavioral disorders
d. When the cat has cardiovascular issues
24. Which drug is known for not generating active metabolites and is useful in treating elderly patients with compromised hepatic function?
a. Diazepam
b. Alprazolam
c. Oxazepam
d. Clorazepate
25. Which of the following is a common adverse effect of alprazolam in dogs?
a. Hepatic necrosis
b. Physical dependence
c. Pancreatitis
d. Cardiovascular issues
26. What is the plasma protein binding capacity of buspirone?
a. 85%
b. 90%
c. 95%
d. 98%
27. Which of the following drugs is recommended to be withdrawn gradually to avoid withdrawal symptoms in dogs?
a. Diazepam
b. Alprazolam
c. Lorazepam
d. Buspirone
28. What is the main pharmacokinetic consideration when using diazepam in different species?
a. Species-specific therapeutic efficacy
b. Species-specific adverse effects
c. Interspecies variability in pharmacokinetic parameters
d. Interspecies variability in plasma protein binding
29. Which drug has been used effectively as an appetite stimulant in cats?
a. Diazepam
b. Alprazolam
c. Oxazepam
d. Lorazepam
30. For which behavioral disorder in dogs is clorazepate commonly used?
a. Generalized anxiety disorder
b. Storm phobia
c. Separation anxiety
d. Urine spraying behavior
31. Which of the following benzodiazepines is known to have minimal CNS depressant effects?
a. Diazepam
b. Buspirone
c. Clorazepate
d. Alprazolam
32. Which adverse effect is commonly associated with chlordiazepoxide?
a. Ataxia
b. Renal dysfunction
c. Cardiomyopathy
d. Hyperactivity
33. Why is buspirone considered a nonsedating anxiolytic?
a. It does not affect dopamine receptors.
b. It does not produce psychomotor disturbance or disinhibition.
c. It has a very short half-life.
d. It binds minimally to plasma proteins.
34. Which of the following is a recommended combination therapy for managing storm phobia in dogs?
a. Alprazolam and clomipramine
b. Diazepam and fluoxetine
c. Oxazepam and clomipramine
d. Lorazepam and fluoxetine
35. Which drug can cross the placental barrier and is contraindicated in pregnant females due to the risk of teratogenicity?
a. Clorazepate
b. Buspirone
c. Alprazolam
d. Diazepam
36. Which class of drugs, unlike benzodiazepines (BZDs), is not associated with withdrawal effects or dependence, and has a lower potential for abuse?
a) Selective serotonin reuptake inhibitors (SSRIs)
b) Monoamine oxidase inhibitors (MAOIs)
c) Tricyclic antidepressants (TCAs)
d) Progestins
37. Which neurotransmitters do antidepressants primarily modulate to exert their therapeutic effects?
a) Dopamine and acetylcholine
b) Norepinephrine and serotonin
c) GABA and glutamate
d) Histamine and adrenaline
38. Which statement regarding the mechanism of action of TCAs is correct?
a) TCAs primarily work by blocking dopamine reuptake.
b) TCAs have selective inhibitory effects on monoamine oxidase (MAO).
c) TCAs block the reuptake of norepinephrine (NE) and serotonin (5-HT) into the presynaptic terminal.
d) TCAs exert their effects mainly by enhancing GABAergic neurotransmission.
39. Which side effect is commonly associated with tricyclic antidepressants (TCAs)?
a) Hyperactivity
b) Hypertension
c) Hypoglycemia
d) Mild sedation
40. Which factor contributes to the delayed onset of therapeutic effects of antidepressants?
a) Decreased levels of norepinephrine (NE) and serotonin (5-HT)
b) Immediate binding to postsynaptic receptors
c) Enhanced sensitivity of presynaptic receptors
d) Altered neurotransmitter metabolism
41. Which neurotransmitter receptor is NOT affected by tricyclic antidepressants (TCAs)?
a) Muscarinic receptors
b) Adrenergic receptors
c) Dopaminergic receptors
d) Histaminergic receptors
42. Which adverse effect is specifically associated with the use of TCAs in geriatric patients and animals with compromised hepatic function?
a) Hypertension
b) Hyperactivity
c) Gastrointestinal disturbances
d) Sedation
43. Which tricyclic antidepressant (TCA) is commonly used for the treatment of aggression, self-induced mutilation, and separation anxiety in dogs?
a) Clomipramine
b) Amitriptyline
c) Imipramine
d) Nortriptyline
44. Which statement regarding the pharmacokinetics of amitriptyline is true?
a) It has a short elimination half-life in dogs.
b) It is metabolized primarily by the kidneys.
c) It is excreted unchanged in the feces.
d) It is rapidly absorbed from the gastrointestinal tract.
45. What is the major metabolite of clomipramine implicated in its antimuscarinic effects?
a) Desmethylclomipramine
b) Nortriptyline
c) Imipramine
d) Triptyline
46. Which adverse effect is NOT commonly associated with the use of clomipramine?
a) Sedation
b) Regurgitation
c) Hyperactivity
d) Urinary retention
47. Which contraindication is specific to the use of clomipramine?
a) History of epilepsy
b) Hypersensitivity to benzodiazepines
c) Glaucoma
d) Urinary incontinence
48. What is the primary mechanism of action of imipramine?
a) Blockade of dopamine receptors
b) Inhibition of acetylcholinesterase
c) Blocking of serotonin (5-HT) reuptake
d) Enhancement of GABAergic neurotransmission
49. In which species is imipramine used for the treatment of ejaculatory dysfunction?
a) Dogs
b) Cats
c) Horses
d) Birds
50. Which statement regarding the pharmacokinetics of imipramine is correct?
a) It has a long elimination half-life in dogs.
b) It is primarily excreted unchanged in the urine.
c) It undergoes extensive metabolism in the liver.
d) Its plasma protein binding is less than 50%.
51. Which of the following statements regarding the pharmacokinetics of imipramine is correct?
a. It undergoes extensive renal elimination.
b. Its plasma protein binding is approximately 30%.
c. Hepatic first-pass metabolism results in high blood levels of imipramine’s active metabolite, desipramine.
d. It exhibits a rapid onset of action within 30 minutes of oral administration.
52. What is a common adverse effect observed in horses and cattle following administration of imipramine?
a. Urinary retention
b. Hemolysis and discolored urine
c. Bradycardia
d. Hypertension
53. Doxepin is contraindicated in animals with a history of:
a. Anxiety disorders
b. Hypoglycemia
c. Glaucoma
d. Osteoarthritis
54. Which enzyme does paroxetine primarily inhibit?
a. CYP2D6
b. CYP1A2
c. CYP3A4
d. CYP2C9
55. What is the main therapeutic use of SSRIs in cats?
a. Treatment of separation anxiety
b. Management of dominance-related aggression
c. Control of urine spraying behavior
d. Treatment of acral lick dermatitis
56. What is the predominant adverse effect of fluoxetine reported in dogs?
a. Sedation
b. Constipation
c. Panting
d. Hypoglycemia
57. In humans, which enzyme metabolizes sertraline?
a. CYP2D6
b. CYP3A4
c. CYP1A2
d. CYP2C9
58. What is the elimination half-life of doxepin in humans?
a. 2-6 hours
b. 12-25 hours
c. 8-25 hours
d. 24 hours
59. Which statement about fluoxetine is true?
a. It has a short elimination half-life in dogs.
b. It is metabolized to a more potent active metabolite.
c. Its plasma protein binding is approximately 50%.
d. It is primarily eliminated unchanged in urine.
60. What is the primary mechanism of action of doxepin?
a. Inhibition of serotonin reuptake
b. Inhibition of norepinephrine reuptake
c. Antagonism of histamine receptors
d. Blockade of dopamine receptors
61. What is the primary route of excretion for sertraline metabolites?
a. Urine
b. Feces
c. Sweat
d. Saliva
62. Which statement regarding the pharmacokinetics of SSRIs is accurate?
a. They are primarily metabolized in the kidneys.
b. They have a rapid onset of action within minutes of administration.
c. They inhibit several isoforms of CYP450 liver enzymes.
d. They reach peak plasma levels within 1-2 hours after oral administration.
63. What adverse effect is particularly associated with the use of paroxetine in dogs?
a. Mydriasis
b. Hypotension
c. Anorexia
d. Hyperactivity
64. Which enzyme does fluoxetine primarily inhibit?
a. CYP1A2
b. CYP3A4
c. CYP2D6
d. CYP2C9
65. What is the primary therapeutic use of doxepin in small animals?
a. Treatment of diabetes mellitus
b. Management of psychogenic dermatitis related to anxiety
c. Control of heartworm disease
d. Prevention of flea infestation
66. What is a common adverse effect observed in humans following administration of SSRIs?
a. Hypertension
b. Hyperglycemia
c. Diarrhea
d. Bradycardia
67. What is the main mechanism of action of SSRIs?
a. Blockade of dopamine receptors
b. Inhibition of norepinephrine reuptake
c. Inhibition of serotonin reuptake
d. Antagonism of histamine receptors
68. What is the primary metabolite of doxepin?
a. Desipramine
b. Desmethyldoxepin
c. Norfluoxetine
d. N-desmethylsertraline
69. Which statement about the pharmacokinetics of SSRIs is correct?
a. They are primarily excreted unchanged in urine.
b. They reach peak plasma levels within 30-60 minutes after oral administration.
c. They have a slow onset of therapeutic effect, typically requiring 3-4 weeks.
d. They are not metabolized in the liver.
70. Which adverse effect is particularly associated with the use of sertraline in cats?
a. Panting
b. Urinary retention
c. Sedation
d. Mydriasis
71. Which medication is primarily used for the treatment of aggression and compulsive disorders in both cats and dogs, particularly for maternal aggression?
a. Fluvoxamine
b. Selegiline
c. Megestrol acetate
d. Medroxyprogesterone acetate
72. What is the approximate plasma protein binding percentage of fluvoxamine?
a. 90%
b. 80%
c. 70%
d. 60%
73. What is the elimination half-life of fluvoxamine in dogs?
a. Approximately 10 hours
b. Approximately 20 hours
c. Approximately 15 hours
d. Approximately 30 hours
74. Which adverse effect may occur when fluvoxamine is given concomitantly with benzodiazepines (BZDs)?
a. Increased appetite
b. Decreased clearance of BZDs
c. Decreased blood pressure
d. Reduced anxiety
75. Selegiline is primarily an inhibitor of:
a. Monoamine oxidase-A
b. Monoamine oxidase-B
c. Monoamine oxidase-C
d. Both MAO-A and MAO-B
76. What is the primary mechanism of action of selegiline?
a. Inhibition of serotonin reuptake
b. Inhibition of dopamine release
c. Selective inhibition of MAO-B
d. Enhancement of GABAergic neurotransmission
77. Selegiline is FDA-approved for the treatment of which disorder in elderly dogs?
a. Canine cognitive dysfunction (CCD)
b. Anxiety disorders
c. Dermatological conditions
d. Chronic pain
78. What is the bioavailability of selegiline in dogs?
a. 100%
b. 90%
c. 80%
d. 10%
79. What is the primary metabolite of selegiline responsible for some sympathomimetic effects?
a. Methamphetamine
b. Amphetamine
c. N-desmethylselegiline
d. Dopamine
80. In dogs, what is the approximate elimination half-life (t 1/2) of selegiline?
a. Approximately 40 minutes
b. Approximately 60 minutes
c. Approximately 80 minutes
d. Approximately 100 minutes
81. Which medication is primarily used for the management of sexually dimorphic behavior in dogs and cats?
a. Fluvoxamine
b. Selegiline
c. Megestrol acetate
d. Medroxyprogesterone acetate
82. What is the main therapeutic effect attributed to progestins in behavioral management?
a. Inhibition of serotonin reuptake
b. Enhancement of dopamine release
c. Antiandrogenic and calming effect on the limbic system
d. Activation of GABA receptors
83. Which synthetic progestin is FDA-approved for the postponement of estrus and the alleviation of pseudo-pregnancy in dogs?
a. Megestrol acetate
b. Medroxyprogesterone acetate
c. Fluoxetine
d. Selegiline
84. What are the most prevalent side effects associated with megestrol acetate use in dogs and cats?
a. Hypertension and tachycardia
b. Sedation, polyphagia, and polydipsia
c. Increased aggression and anxiety
d. Gastrointestinal bleeding
85. What is the route of administration for medroxyprogesterone acetate (MPA) in cats, and how often is it typically administered?
a. Intravenous, once a month
b. Intramuscular or subcutaneous, once a month
c. Oral, once daily
d. Topical, as needed
Anesthetics
1. What is the primary difference between local and general anesthesia?
a. Local anesthesia induces unconsciousness, while general anesthesia does not
b. Local anesthesia blocks nerve impulse conduction, while general anesthesia affects the brain and spinal cord
c. General anesthesia is administered topically, while local anesthesia requires injection
d. General anesthesia is reversible, while local anesthesia is not
2. Which of the following is NOT a method of administering local anesthesia?
a. Topically
b. Intravenously
c. By injection into tissues surrounding peripheral nerve endings
d. Into joint spaces
3. What is the mechanism of action of local anesthetics?
a. Activation of voltage-gated Na+ channels
b. Inhibition of the flux of Na+ through voltage-gated Na+ channels
c. Blocking of K+ channels
d. Stimulation of neurotransmitter release
4. Which structural component is NOT found in local anesthetics?
a. Aromatic group
b. Intermediate bond
c. Quaternary amine
d. Tertiary amine
5. What is the purpose of adding epinephrine to some local anesthetics?
a. To enhance their lipid solubility
b. To prolong their duration of action
c. To increase their pH
d. To decrease their protein binding
6. Which nerve fibers are historically considered easier to block with local anesthetics?
a. A-δ fibers
b. Large diameter myelinated fibers
c. C fibers
d. Sensory fibers
7. What is the primary site of action of inhalant anesthetics?
a. Muscles
b. Peripheral nerves
c. Brain and spinal cord
d. Heart
8. What is the main function of lidocaine when infused intravenously in horses?
a. To induce anesthesia
b. To control arrhythmias
c. To increase intestinal motility
d. To decrease blood pressure
9. Which statement regarding the mechanism of action of inhalant anesthetics is accurate?
a. It is well-understood and consistent across all agents
b. It primarily involves stimulation of neurotransmitter release
c. It is unknown and subject to ongoing research
d. It exclusively affects the peripheral nervous system
10. What is the first sign of central nervous system toxicity associated with local anesthetics?
a. Tonic-clonic seizures
b. Skeletal muscle twitches
c. Hypotension
d. Prolongation of PR and QRS intervals
11. Which nerve fiber type has been shown to be the last to be blocked by lidocaine?
a. A-δ fibers
b. Large diameter myelinated fibers
c. C fibers
d. Sensory fibers
12. How does the addition of epinephrine affect the systemic absorption of local anesthetics?
a. It increases systemic absorption
b. It has no effect on systemic absorption
c. It decreases systemic absorption
d. It depends on the specific local anesthetic used
13. What role does the Na+, K+-ATPase pump play in the action potential process?
a. It facilitates Na+ influx during depolarization
b. It maintains the resting membrane potential by transporting Na+ out of the cell
c. It inhibits K+ efflux during repolarization
d. It stimulates neurotransmitter release
14. Which characteristic of local anesthetics correlates with potency and duration of action?
a. Protein binding
b. pKa
c. Lipid solubility
d. Hydrophilicity
15. What is the primary function of lidocaine when used as a constant rate IV infusion?
a. To induce anesthesia
b. To control arrhythmias
c. To produce analgesia
d. To decrease intestinal motility
16. What is the primary function of epinephrine when added to some local anesthetics?
a. To enhance systemic absorption
b. To increase protein binding
c. To prolong the duration of action
d. To decrease lipid solubility
17. Which type of nerves are historically considered easier to block with local anesthetics?
a. Afferent fibers
b. Efferent fibers
c. C fibers
d. Myelinated fibers
18. How does the pH of the environment affect the effectiveness of local anesthetics?
a. Acidic environments increase effectiveness
b. Alkaline environments decrease effectiveness
c. pH has no effect on effectiveness
d. Basic environments increase effectiveness
19. Which statement regarding the pharmacokinetics of local anesthetics is true?
a. Ester-linked local anesthetics are metabolized in the liver
b. Amide-linked local anesthetics undergo hydrolysis by cholinesterase
c. Cats are less likely to develop toxicity from amide-linked local anesthetics
d. Lipid solubility is inversely proportional to potency and duration of action
20. What is the primary difference between the onset of action of local anesthetics with different pKa values?
a. Drugs with higher pKa values have a slower onset of action
b. Drugs with lower pKa values have a slower onset of action
c. Drugs with higher pKa values have a more potent onset of action
d. Drugs with lower pKa values have a more potent onset of action
21. Which observation supports the hypothesis of a single mechanism of action for inhalant anesthetics?
a) The correlation between anesthetic potency and solubility in olive oil.
b) The reversal of anesthetic effect with increasing atmospheric pressure.
c) The additive effect of simultaneous administration of two anesthetics.
d) The relationship between blood partition coefficient and speed of induction.
22. What is the purpose of determining the Minimum Alveolar Concentration (MAC) of an inhalant anesthetic?
a) To measure the rate of induction and recovery.
b) To assess the anesthetic’s solubility in blood.
c) To establish surgical anesthesia levels.
d) To prevent diffusion hypoxia during recovery.
23. Which factor does NOT affect the Minimum Alveolar Concentration (MAC) value for a patient?
a) Advanced age
b) Patient gender
c) Hypertension
d) Hypoxemia
24. According to the Meyer-Overton Observation, how does lipid solubility correlate with anesthetic potency?
a) Positively
b) Negatively
c) No correlation
d) Inversely
25. What effect does a high blood
partition coefficient have on the induction and recovery of anesthesia?
a) Speeds up induction and recovery
b) Slows down induction and recovery
c) Has no effect on induction and recovery
d) Decreases the need for high initial concentrations
26. What does the ratio of concentration of anesthetic in the alveolus (FA) to the concentration inspired (FI) provide information about?
a) Speed of induction
b) Anesthetic potency
c) Blood
d) Various inhalant anesthetics
27. How is the concentration of anesthetic in the brain controlled during inhalant anesthesia?
a) By controlling the inspired concentration of anesthetic
b) By controlling the cardiac output
c) By administering high concentrations to the lungs initially
d) By manipulating the blood
partition coefficient
28. What is the second gas effect associated with the administration of nitrous oxide?
a) Decreased absorption of other components of the alveolus
b) Enhanced absorption of other components of the alveolus
c) Increased elimination of other anesthetics
d) Decreased elimination of nitrous oxide
29. What effect does nitrous oxide have on myocardial function?
a) Increases myocardial contractility
b) Depresses myocardial function
c) Sensitizes the myocardium to epinephrine
d) Stimulates the parasympathetic nervous system
30. Which adverse effect is associated with the administration of nitrous oxide in anesthetized animals?
a) Hypertension
b) Bradycardia
c) Hypoxemia
d) Hypothermia
31. What is the primary reason for the rapid induction and recovery of anesthesia with isoflurane?
a) High blood
partition coefficient
b) Rapid metabolism
c) Low solubility in blood
d) CNS stimulant effect
32. How does isoflurane affect cardiovascular function?
a) Increases arterial blood pressure
b) Increases systemic vascular resistance
c) Decreases cardiac output
d) Decreases stroke volume
33. What is the effect of isoflurane on cerebral blood flow?
a) Decreases at high multiples of MAC
b) Increases at low multiples of MAC
c) Remains unchanged at all levels of anesthesia
d) Increases at all levels of anesthesia
34. Which organ toxicity is NOT associated with the use of isoflurane?
a) Hepatic toxicity
b) Renal toxicity
c) Cardiac toxicity
d) Neurologic dysfunction
35. What is the specific gravity of isoflurane?
a) Higher than halothane
b) Lower than halothane
c) Similar to halothane
d) Not mentioned in the text
36. What adverse effect is associated with the accumulation of nitrous oxide in gas-filled spaces?
a) Hypotension
b) Hyperthermia
c) Pernicious anemia
d) Distention of the spaces
37. What is the primary therapeutic use of nitrous oxide?
a) Surgical anesthesia in large animals
b) Maintenance of general anesthesia in small animals
c) Analgesia in combination with other anesthetics
d) Induction of anesthesia in equine patients
38. How is the concentration of nitrous oxide and oxygen determined during administration?
a) By measuring the blood
partition coefficient
b) By using a vaporizer
c) By adjusting flowmeters
d) By calculating the MAC value
39. Which gas is produced when nitrous oxide dissociates during combustion?
a) Nitrogen
b) Oxygen
c) Carbon dioxide
d) Nitric oxide
40. Which inhalant anesthetic agent is considered the current agent of choice for animals with suspected increases in intracranial pressure?
a) Desflurane
b) Sevoflurane
c) Isoflurane
d) Halothane
41. What is the primary metabolic fate of sevoflurane in the body?
a) Metabolized by the liver to fluoride ion and hexafluoroisopropanol
b) Exhaled unchanged
c) Converted to carbon dioxide and water
d) Converted to inactive metabolites by the kidneys
42. Which inhalant anesthetic agent has been associated with malignant hyperthermia?
a) Desflurane
b) Sevoflurane
c) Isoflurane
d) Halothane
43. What is the primary mechanism of action of barbiturates as anesthetics?
a) Activation of NMDA receptors
b) Inhibition of acetylcholinesterase
c) Activation of gamma-aminobutyric acid (GABA)-gated chloride channels
d) Blockade of sodium channels
44. Which barbiturate is considered one of the drugs of choice for induction of anesthesia in animals with suspected increased intracranial pressure?
a) Methohexital
b) Pentobarbital
c) Thiopental
d) Halothane
45. What is the effect of thiobarbiturates on cerebral blood flow?
a) Decreases cerebral blood flow
b) Increases cerebral blood flow
c) No effect on cerebral blood flow
d) Depends on the dose administered
46. Which inhalant anesthetic agent requires a sophisticated vaporizer due to its high vapor pressure?
a) Isoflurane
b) Sevoflurane
c) Desflurane
d) Halothane
47. What is the primary renal effect of isoflurane?
a) Increased renal blood flow
b) Decreased glomerular filtration rate
c) Increased urine production
d) No effect on renal function
48. Which inhalant anesthetic agent has been approved for veterinary use in dogs?
a) Desflurane
b) Sevoflurane
c) Isoflurane
d) Halothane
49. What is the main concern associated with the use of sevoflurane and desiccated soda lime in anesthetic machines?
a) Formation of carbon monoxide
b) Excessive heat production
c) Spontaneous fire in the breathing circuit
d) Chemical reaction leading to toxic byproducts
50. Which inhalant anesthetic agent has not been associated with any organ toxicities due to its inertness?
a) Isoflurane
b) Sevoflurane
c) Desflurane
d) Halothane
51. What is the primary effect of sevoflurane on hepatic blood flow?
a) Increased hepatic blood flow
b) Decreased hepatic blood flow
c) No effect on hepatic blood flow
d) Increased hepatic clearance of drugs
52. Which inhalant anesthetic agent has the lowest potency compared to others in use?
a) Isoflurane
b) Sevoflurane
c) Desflurane
d) Halothane
53. What is the primary pharmacokinetic characteristic of thiobarbiturates?
a) Slow onset of action
b) Rapid redistribution in the body
c) Prolonged duration of action
d) High protein binding
54. Which barbiturate is more rapidly metabolized than thiobarbiturates due to its higher lipid solubility?
a) Pentobarbital
b) Thiopental
c) Methohexital
d) Halothane
55. What is the primary adverse effect associated with a large IV dose of thiobarbiturates?
a) Allergic reactions
b) Prolonged recovery
c) Cardiac arrhythmias
d) Local irritation
56. Which barbiturate is commonly used as a primary ingredient in euthanasia agents?
a) Methohexital
b) Pentobarbital
c) Thiopental
d) Halothane
57. What is the effect of barbiturates on cerebral oxygen consumption?
a) Increases cerebral oxygen consumption
b) Decreases cerebral oxygen consumption
c) No effect on cerebral oxygen consumption
d) Depends on the dose administered
58. Which barbiturate is considered safe for use during cesarean section due to its rapid redistribution in the dam and fetus?
a) Pentobarbital
b) Thiopental
c) Methohexital
d) Halothane
59. What is the primary effect of barbiturates on cerebral blood volume?
a) Increases cerebral blood volume
b) Decreases cerebral blood volume
c) No effect on cerebral blood volume
d) Depends on the dose administered
60. What is the primary mechanism of action of propofol?
a) Inhibition of NMDA receptors
b) Activation of GABA receptors
c) Inhibition of cytochrome P450 enzymes
d) Blockade of acetylcholine receptors
61. Which of the following adverse effects is commonly associated with ketamine administration in horses and dogs?
a) Hypertension
b) Excessive salivation
c) Myoclonic twitching
d) Respiratory depression
62. Which drug combination is frequently used with ketamine in dogs and cats to prevent seizures and provide muscle relaxation?
a) Ketamine and xylazine
b) Ketamine and guaifenesin
c) Ketamine and midazolam
d) Ketamine and diazepam
63. What is the primary pharmacological effect of etomidate?
a) Increased cerebral blood flow
b) Depression of cardiovascular function
c) Inhibition of adrenal steroidogenesis
d) Prolonged duration of anesthesia
64. Which drug is contraindicated in animals with corneal ulcers or lacerations due to its potential to increase intraocular pressure?
a) Ketamine
b) Propofol
c) Telazol
d) Etomidate
65. What is the primary cardiovascular effect of cyclohexylamines in healthy animals?
a) Decreased heart rate
b) Increased blood pressure
c) Decreased cardiac output
d) Vasodilation
66. Which drug is characterized by a rapid onset of action and smooth induction of anesthesia, making it ideal for short procedures or prior to inhalant anesthesia?
a) Ketamine
b) Tiletamine
c) Propofol
d) Etomidate
67. What is the primary CNS effect of long-acting barbiturates such as phenobarbital?
a) Increased muscle relaxation
b) Enhanced activity in the limbic system
c) Depression of thalamoneocortical function
d) Activation of the reticular activating system
68. Which drug is used primarily as an anticonvulsant at subanesthetic doses rather than as a general anesthetic?
a) Etomidate
b) Propofol
c) Ketamine
d) Phenobarbital
69. What adverse effect may result from the increased muscle activity associated with telazol administration?
a) Hypotension
b) Hyperthermia
c) Bradycardia
d) Respiratory depression
70. Which drug should be avoided in cases with intracranial hypertension such as head trauma or intracranial tumors due to its effect on cerebral blood flow and intracranial pressure?
a) Propofol
b) Etomidate
c) Ketamine
d) Tiletamine
71. What is the primary pharmacokinetic characteristic of ketamine in cats, calves, and horses?
a) Rapid metabolism by hepatic hydrolysis
b) Renal excretion of unchanged drug
c) Prolonged half-life of 6-12 hours
d) Accumulation following repeated doses
72. Which drug combination is contraindicated in dogs or cats with reduced cardiopulmonary reserve due to its cardiovascular effects?
a) Ketamine and xylazine
b) Ketamine and guaifenesin
c) Propofol and midazolam
d) Telazol and butorphanol
73. What is the primary therapeutic use of etomidate?
a) Long-term anesthesia maintenance
b) Sedation in feral cats
c) IV induction of anesthesia for short procedures
d) Prevention of seizures in dogs
74. Which drug is formulated in a 1% aqueous emulsion containing soybean oil, egg lecithin, and glycerol?
a) Tiletamine
b) Etomidate
c) Propofol
d) Ketamine
75. What is the primary mechanism of action of etomidate?
a. Enhancement of GABAergic neurotransmission
b. Stimulation of the reticular formation
c. Inhibition of calcium influx
d. Activation of neocortical sleep patterns
76. Which of the following is a therapeutic use of etomidate in veterinary medicine?
a. Long-term anesthesia in large animals
b. Sedation for prolonged surgeries in cats
c. Induction of anesthesia for short procedures in dogs and cats
d. Treatment of chronic pain in horses
77. What adverse effect of etomidate can be prevented by preinduction sedation with tranquilizers or opioids?
a. Hypertension
b. Myoclonus and excitement
c. Respiratory depression
d. Cardiac arrhythmias
78. Guaifenesin, a central muscle relaxant, primarily affects which part of the nervous system?
a. Peripheral nervous system
b. Sympathetic nervous system
c. Autonomic nervous system
d. Central nervous system
79. Which adverse effect of guaifenesin is associated with concentrations exceeding 10% in cattle or 12.5% in horses?
a. Urticaria
b. Hemolysis and hemoglobinuria
c. Perivascular inflammation
d. Prolonged recovery times
80. Methocarbamol, a guaifenesin-analog, is primarily used for which condition in animals?
a. Chronic pain management in horses
b. Sedation prior to anesthesia in dogs
c. Muscle relaxation in equine acute rhabdomyolysis
d. Treatment of heartworm disease in cats
81. What is the primary route of administration for methocarbamol in veterinary medicine?
a. Intravenous
b. Intramuscular
c. Subcutaneous
d. Oral
82. Which statement regarding the pharmacokinetics of methocarbamol is true?
a. It has a long plasma elimination half-life in humans
b. It is primarily excreted unchanged in the feces
c. It has limited distribution into tissues, excluding the CNS
d. It is metabolized by hepatic cytochrome P450 enzymes
83. What adverse effect of methocarbamol is particularly emphasized due to its irritating nature?
a. Urticaria
b. Hemolysis
c. Extravasation
d. Bradycardia
84. Which of the following is a pharmacologic effect of guaifenesin in animals?
a. Increased heart rate
b. Decreased respiratory function
c. Enhanced diaphragmatic function
d. Analgesia accompanied by muscle relaxation
Download the PDF files containing the MCQs sets using the provided links above. Allocate a suitable time to attempt each set of questions. Answer each question to the best of your knowledge. After completing each set, review your answers and identify areas for improvement. Utilize these MCQs as a tool for reinforcing your understanding of Veterinary Pharmacology and Toxicology.
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Veterinary Internal Medicine MCQs With Answers PDF Free Download [Direct Link]
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