Pharmacology and Therapeutics Flashcards

Which class of medications is first-line for managing hypertension in a patient with concurrent type 2 diabetes and proteinuria?

Answer: ACE inhibitors or ARBs

ACE inhibitors and ARBs are first-line in diabetic patients with proteinuria because they reduce intraglomerular pressure and slow nephropathy progression.

A patient taking warfarin is started on rifampin. How should warfarin dosing be adjusted?

Answer: Increase warfarin dose; rifampin induces CYP450 enzymes

Rifampin is a potent CYP450 inducer that accelerates warfarin metabolism, reducing its anticoagulant effect and requiring a higher dose.

Which antibiotic class is associated with QT prolongation and must be used cautiously in patients on antiarrhythmics?

Answer: Fluoroquinolones

Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) can prolong the QT interval, increasing the risk of torsades de pointes especially with other QT-prolonging drugs.

Metformin is contraindicated in patients with an eGFR below what threshold due to risk of lactic acidosis?

Answer: 30 mL/min/1.73m²

Metformin should be discontinued when eGFR falls below 30 mL/min/1.73m² because reduced renal clearance allows metformin accumulation and lactic acid buildup.

Which opioid analgesic is safest to use in patients with chronic kidney disease because it lacks active renally cleared metabolites?

Answer: Fentanyl

Fentanyl is metabolized to inactive compounds and does not accumulate in renal failure, making it safer than morphine whose active metabolite (M6G) can cause toxicity.

Statins exert their primary lipid-lowering effect by inhibiting which enzyme?

Answer: HMG-CoA reductase

Statins competitively inhibit HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis, reducing LDL-C levels.