NAVLE Veterinary Pharmacology 4 — Questions and Answers
Question 1: A dog receives an overdose of acepromazine. Which statement about acepromazine reversal is correct?
- Reversal can be achieved with atipamezole
- There is no specific reversal agent; treatment is supportive (Correct answer)
- Naloxone effectively reverses acepromazine sedation
- Flumazenil fully reverses phenothiazine effects
Correct answer: There is no specific reversal agent; treatment is supportive
Acepromazine, a phenothiazine tranquilizer, has no specific reversal agent; management consists of supportive care including IV fluids and vasopressors for hypotension.
Question 2: Which class of drugs can cause crystalluria and urinary obstruction in dogs, particularly in acidic urine?
- Fluoroquinolones
- Sulfonamides (Correct answer)
- Tetracyclines
- Aminoglycosides
Correct answer: Sulfonamides
Sulfonamides can precipitate in acidic urine and form crystals, potentially causing crystalluria, hematuria, and renal tubular obstruction.
Question 3: A cattle producer wants to treat a cow with bacterial pneumonia. Which beta-lactam antibiotic has an approved long-acting formulation for cattle?
- Ampicillin
- Ceftiofur (Correct answer)
- Penicillin G procaine
- Amoxicillin
Correct answer: Ceftiofur
Ceftiofur (as ceftiofur crystalline free acid) has a long-acting formulation approved in cattle that provides therapeutic concentrations for several days.
Question 4: What is the primary concern when using ketamine as the sole anesthetic in a dog?
- Severe respiratory depression
- Inadequate muscle relaxation and increased muscle tone (Correct answer)
- Prolonged recovery
- Profound hypotension
Correct answer: Inadequate muscle relaxation and increased muscle tone
Ketamine alone causes increased muscle tone and catalepsy rather than muscle relaxation, so it is typically combined with a benzodiazepine or alpha-2 agonist for adequate relaxation.
Question 5: Which drug used in cattle to synchronize estrus can cause luteolysis by acting on the corpus luteum?
- GnRH
- Prostaglandin F2α (PGF2α) (Correct answer)
- Progesterone
- Estradiol
Correct answer: Prostaglandin F2α (PGF2α)
Prostaglandin F2α causes regression of the corpus luteum (luteolysis), leading to a decrease in progesterone and allowing the next follicular wave to result in estrus.
Question 6: Which antifungal drug works by inhibiting the enzyme lanosterol 14-alpha-demethylase, disrupting ergosterol synthesis?
- Amphotericin B
- Griseofulvin
- Fluconazole (Correct answer)
- Nystatin
Correct answer: Fluconazole
Fluconazole (and other azole antifungals) inhibit lanosterol 14-alpha-demethylase, blocking ergosterol synthesis and disrupting fungal cell membrane integrity.
Question 7: A dog with dilated cardiomyopathy is started on digoxin. Which electrolyte abnormality increases the risk of digoxin toxicity?
- Hyperkalemia
- Hypokalemia (Correct answer)
- Hypernatremia
- Hypercalcemia
Correct answer: Hypokalemia
Hypokalemia potentiates digoxin toxicity because potassium and digoxin compete for the same binding site on Na+/K+-ATPase; low potassium increases digoxin binding and effect.
NAVLE Veterinary Pharmacology 4
A dog receives an overdose of acepromazine.
Which statement about acepromazine reversal is correct?