Clinical Pharmacy Flashcards

A patient with community-acquired pneumonia (CAP) and penicillin allergy (anaphylaxis) requires antibiotic therapy. Which agent is most appropriate?

Answer: Azithromycin monotherapy for outpatient mild CAP

For mild outpatient CAP with true penicillin anaphylaxis, azithromycin monotherapy is guideline-recommended and avoids cross-reactivity risk.

What is the primary advantage of using pharmacokinetic/pharmacodynamic (PK/PD) modeling in antibiotic dosing?

Answer: It optimizes dosing to maximize efficacy while minimizing toxicity and resistance

PK/PD modeling links drug exposure to microbiological outcomes, allowing individualized dosing that maximizes target attainment while limiting toxicity and resistance selection.

Which mechanism explains the nephrotoxicity of amphotericin B deoxycholate?

Answer: Direct binding to renal tubular cell ergosterol causing cytotoxicity and vasoconstriction

Amphotericin B binds ergosterol-like sterols in renal tubular cells and induces afferent arteriolar vasoconstriction, causing direct nephrotoxicity.

A 55-year-old patient on warfarin starts taking St. John's Wort. What pharmacokinetic outcome is expected?

Answer: Decreased warfarin levels due to CYP3A4 induction

St. John's Wort is a potent inducer of CYP3A4 and P-glycoprotein, accelerating warfarin metabolism and reducing anticoagulation.

When counseling a patient on albuterol inhaler technique, which step is most critical for effective drug delivery to the lower airways?

Answer: Inhaling slowly and deeply while actuating the inhaler

A slow, deep inhalation coordinates with actuation to maximize deposition of drug particles in the lower airways rather than the oropharynx.

A patient newly diagnosed with type 2 diabetes has an HbA1c of 9.2%. Per ADA guidelines, what is the initial pharmacotherapy recommendation?

Answer: Metformin plus a second agent or insulin depending on symptoms

ADA guidelines recommend dual therapy (metformin + a second agent) or insulin for HbA1c ≥9% to achieve glycemic targets more rapidly.

Which lab value indicates adequate anticoagulation with unfractionated heparin (UFH) in venous thromboembolism treatment?

Answer: aPTT 1.5–2.5 times the control value

UFH therapeutic effect is monitored by aPTT targeted at 1.5–2.5 times the institutional control value, corresponding to anti-Xa levels of 0.3–0.7 IU/mL.