Physician Assistant Pharmaceutical Therapeutics 5 — Questions and Answers
Question 1: A patient with systolic heart failure (HFrEF) is on optimal medical therapy. Which medication has shown mortality reduction and is recommended by ACC/AHA guidelines as first-line?
- Digoxin
- Spironolactone alone
- Carvedilol (beta-blocker) (Correct answer)
- Furosemide
Correct answer: Carvedilol (beta-blocker)
Beta-blockers including carvedilol, metoprolol succinate, and bisoprolol reduce mortality in stable HFrEF and are guideline-directed first-line therapy.
Question 2: Which benzodiazepine is safest in elderly patients due to its lack of active metabolites and shorter half-life?
- Diazepam
- Chlordiazepoxide
- Lorazepam (Correct answer)
- Clonazepam
Correct answer: Lorazepam
Lorazepam undergoes direct glucuronidation with no active metabolites and is preferred in elderly patients per the Beers Criteria considerations.
Question 3: A patient on rifampin for tuberculosis has a subtherapeutic oral contraceptive effect. What is the mechanism?
- Competitive binding at estrogen receptors
- Inhibition of estrogen absorption in the gut
- Induction of CYP3A4 increasing estrogen metabolism (Correct answer)
- Increased renal estrogen excretion
Correct answer: Induction of CYP3A4 increasing estrogen metabolism
Rifampin is a potent CYP3A4 inducer that accelerates estrogen and progestin metabolism, reducing plasma contraceptive concentrations.
Question 4: Which second-generation antipsychotic is associated with the highest risk of metabolic syndrome, weight gain, and new-onset diabetes?
- Aripiprazole
- Ziprasidone
- Clozapine/Olanzapine (Correct answer)
- Lurasidone
Correct answer: Clozapine/Olanzapine
Clozapine and olanzapine carry the highest metabolic risk among atypical antipsychotics; regular monitoring of weight, glucose, and lipids is mandatory.
Question 5: A patient taking an MAO inhibitor for depression eats aged cheese and develops a hypertensive crisis. What is the mechanism?
- Tyramine displaces norepinephrine from nerve terminals causing massive release (Correct answer)
- Tyramine directly activates alpha-2 adrenergic receptors
- Tyramine inhibits renal dopamine clearance
- Tyramine blocks calcium channels
Correct answer: Tyramine displaces norepinephrine from nerve terminals causing massive release
MAO normally metabolizes tyramine; when inhibited, dietary tyramine enters systemic circulation, displacing NE from storage vesicles causing a catecholamine surge.
Question 6: Which antifungal requires monitoring of hepatic function and is associated with QT prolongation due to CYP3A4 inhibition?
- Fluconazole
- Terbinafine
- Voriconazole (Correct answer)
- Nystatin
Correct answer: Voriconazole
Voriconazole is a potent CYP inhibitor that prolongs QT interval and is hepatotoxic; LFTs and ECG monitoring are recommended during therapy.
Question 7: A patient with Clostridium difficile infection (CDI) has a first recurrence after metronidazole treatment. What is the preferred management?
- Repeat metronidazole course
- Oral vancomycin standard course
- Fidaxomicin or vancomycin tapered/pulsed regimen (Correct answer)
- IV metronidazole plus oral vancomycin
Correct answer: Fidaxomicin or vancomycin tapered/pulsed regimen
IDSA guidelines recommend fidaxomicin or a vancomycin tapered/pulsed regimen for first recurrence of CDI to reduce further recurrence rates.
Physician Assistant Pharmaceutical Therapeutics 5
A patient with systolic heart failure (HFrEF) is on optimal medical therapy.
Which medication has shown mortality reduction and is recommended by ACC/AHA guidelines as first-line?