DO Pharmacology and Therapeutics 2 — Questions and Answers
Question 1: A patient prescribed an SSRI for depression develops agitation, hyperthermia, and clonus after adding tramadol. What syndrome is occurring?
- Serotonin syndrome (Correct answer)
- Neuroleptic malignant syndrome
- Malignant hyperthermia
- Anticholinergic toxicity
Correct answer: Serotonin syndrome
Tramadol inhibits serotonin reuptake, and when combined with an SSRI, excessive serotonergic activity causes serotonin syndrome.
Question 2: Which beta-blocker is cardioselective (β1-selective) and preferred in patients with mild asthma requiring heart rate control?
- Metoprolol (Correct answer)
- Propranolol
- Carvedilol
- Labetalol
Correct answer: Metoprolol
Metoprolol is β1-selective and less likely to cause bronchospasm than nonselective agents like propranolol, though caution is still advised in asthma.
Question 3: The antidote for acetaminophen overdose, N-acetylcysteine (NAC), works by which mechanism?
- Replenishing glutathione stores to detoxify NAPQI (Correct answer)
- Directly binding acetaminophen in the gut
- Inhibiting CYP2E1 to reduce toxic metabolite formation
- Alkalinizing urine to enhance excretion
Correct answer: Replenishing glutathione stores to detoxify NAPQI
NAC provides cysteine for glutathione synthesis, replenishing hepatic stores depleted by NAPQI (the toxic acetaminophen metabolite) to prevent liver necrosis.
Question 4: Which drug used for gout acts by inhibiting xanthine oxidase to reduce uric acid production?
- Allopurinol (Correct answer)
- Colchicine
- Probenecid
- Indomethacin
Correct answer: Allopurinol
Allopurinol inhibits xanthine oxidase, blocking conversion of hypoxanthine and xanthine to uric acid, thereby lowering serum urate levels.
Question 5: A patient on lithium develops nausea, tremor, and confusion. Which medication should be reviewed as a potential cause of lithium toxicity?
- Ibuprofen (NSAID) (Correct answer)
- Acetaminophen
- Diphenhydramine
- Amoxicillin
Correct answer: Ibuprofen (NSAID)
NSAIDs reduce renal prostaglandin synthesis, decreasing GFR and lithium clearance, which can rapidly elevate lithium levels to toxic concentrations.
Question 6: Which anticoagulant requires no routine INR monitoring and acts by directly inhibiting thrombin (Factor IIa)?
- Dabigatran (Correct answer)
- Warfarin
- Rivaroxaban
- Apixaban
Correct answer: Dabigatran
Dabigatran (Pradaxa) is a direct thrombin inhibitor that does not require INR monitoring unlike warfarin, and has a predictable pharmacokinetic profile.
DO Pharmacology and Therapeutics 2
A patient prescribed an SSRI for depression develops agitation, hyperthermia, and clonus after adding tramadol.
What syndrome is occurring?