SPEX Pharmacology Flashcards
6 cards from real SPEX practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 SPEX Pharmacology flashcards as text
Which medication requires routine monitoring of serum drug levels due to its narrow therapeutic index?
Answer: Lithium
Lithium has a narrow therapeutic index, requiring regular serum level monitoring to prevent toxicity.
A patient develops 'red man syndrome' during IV infusion. Which drug is responsible?
Answer: Vancomycin
Vancomycin infused too rapidly causes non-immune mast cell degranulation, leading to flushing and erythema known as red man syndrome.
Which antihypertensive is contraindicated in bilateral renal artery stenosis?
Answer: ACE inhibitors
ACE inhibitors reduce efferent arteriolar tone, critically reducing GFR in bilateral renal artery stenosis and risking acute kidney injury.
Which cytochrome P450 enzyme is primarily responsible for metabolizing warfarin and many other drugs?
Answer: CYP2C9
CYP2C9 is the primary enzyme responsible for S-warfarin metabolism, and its inhibition or induction significantly affects INR.
What is the mechanism of action of statins in lowering LDL cholesterol?
Answer: Blocking HMG-CoA reductase
Statins inhibit HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis, indirectly upregulating LDL receptors.
A patient taking rifampin for tuberculosis has reduced efficacy of their oral contraceptive. Why?
Answer: Rifampin induces CYP3A4
Rifampin is a potent CYP3A4 inducer that accelerates metabolism of oral contraceptive hormones, reducing their plasma levels and efficacy.