Pharmaceutical Therapeutics Flashcards
7 cards from real Physician Assistant practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pharmaceutical Therapeutics flashcards as text
A patient with CKD stage 3 is started on metformin. Which creatinine clearance threshold requires discontinuation of metformin?
Answer: < 30 mL/min
Metformin is contraindicated when eGFR falls below 30 mL/min/1.73m² due to risk of lactic acidosis.
Which antibiotic class is most appropriate for empiric treatment of community-acquired pneumonia in an otherwise healthy outpatient with no recent antibiotic use?
Answer: Macrolide monotherapy
IDSA/ATS guidelines recommend macrolide monotherapy (e.g., azithromycin) for healthy outpatients with no comorbidities.
A 65-year-old on warfarin for atrial fibrillation starts clarithromycin. What adjustment is needed?
Answer: Reduce warfarin dose and monitor INR closely
Clarithromycin inhibits CYP3A4 and CYP2C9, reducing warfarin metabolism and increasing INR; dose reduction and close monitoring are required.
Which NSAID is preferred in a patient who requires analgesia and has a history of peptic ulcer disease with H. pylori eradication completed?
Answer: Celecoxib with a PPI
A COX-2 selective inhibitor combined with a PPI provides analgesia with the lowest GI risk in patients with prior ulcer disease.
A patient taking lisinopril develops a dry, nonproductive cough. What is the most appropriate alternative antihypertensive?
Answer: Losartan
ARBs (e.g., losartan) do not cause bradykinin accumulation and are the preferred substitute for ACE inhibitor-induced cough.
Which pharmacokinetic parameter best describes how a drug distributes throughout the body and is used to estimate loading dose?
Answer: Volume of distribution
Volume of distribution (Vd) reflects drug distribution into tissues and is used in the formula: Loading dose = Cp × Vd / bioavailability.
A patient on lithium begins taking ibuprofen for arthritis. Which effect is most likely?
Answer: Increased lithium levels and toxicity risk
NSAIDs reduce prostaglandin-mediated renal lithium excretion, causing lithium accumulation and potential toxicity.