ABPS ABPS Pharmacology & Therapeutics 1 — Questions and Answers
Question 1: Which class of medications is contraindicated in patients with a known hypersensitivity to sulfonamides due to cross-reactivity concerns?
- Thiazide diuretics (Correct answer)
- Beta-blockers
- ACE inhibitors
- Calcium channel blockers
Correct answer: Thiazide diuretics
Thiazide diuretics contain a sulfonamide moiety and may cause cross-reactive hypersensitivity reactions in sulfonamide-allergic patients.
Question 2: A patient on warfarin begins taking rifampin for tuberculosis. What change in INR would you expect?
- Increased INR due to enzyme inhibition
- Decreased INR due to enzyme induction (Correct answer)
- No change in INR
- Unpredictable fluctuations only
Correct answer: Decreased INR due to enzyme induction
Rifampin is a potent CYP450 enzyme inducer that accelerates warfarin metabolism, leading to a decreased INR and reduced anticoagulation effect.
Question 3: Which opioid analgesic is considered safest for use in patients with severe renal impairment?
- Morphine
- Codeine
- Fentanyl (Correct answer)
- Meperidine
Correct answer: Fentanyl
Fentanyl is preferred in renal impairment because it lacks active metabolites that accumulate with decreased renal clearance, unlike morphine or meperidine.
Question 4: A physician prescribes metformin for a newly diagnosed type 2 diabetic. Which condition is an absolute contraindication to metformin use?
- Mild hypertension
- Obesity
- eGFR < 30 mL/min/1.73m² (Correct answer)
- Hypothyroidism
Correct answer: eGFR < 30 mL/min/1.73m²
Severely reduced renal function (eGFR < 30) is an absolute contraindication to metformin due to risk of fatal lactic acidosis from drug accumulation.
Question 5: Which beta-blocker is cardioselective and preferred in patients with mild asthma who require beta-blocker therapy?
- Propranolol
- Carvedilol
- Metoprolol (Correct answer)
- Labetalol
Correct answer: Metoprolol
Metoprolol is a beta-1 selective (cardioselective) blocker that has less effect on bronchial beta-2 receptors, making it preferable in patients with mild reactive airway disease.
Question 6: A patient taking an SSRI is started on tramadol for pain. What serious drug interaction should the prescriber monitor for?
- Hypertensive crisis
- Serotonin syndrome (Correct answer)
- Neuroleptic malignant syndrome
- Anticholinergic toxidrome
Correct answer: Serotonin syndrome
Tramadol inhibits serotonin reuptake and, combined with an SSRI, significantly increases the risk of serotonin syndrome, a potentially life-threatening condition.
ABPS ABPS Pharmacology & Therapeutics 1
Which class of medications is contraindicated in patients with a known hypersensitivity to sulfonamides due to cross-reactivity concerns?