Practice Test Geeks(PSA) Prescribing Safety Assessment Practice Test
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Antimicrobial Prescribing Flashcards

7 cards from real PSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. A patient receiving gentamicin for gram-negative bacteremia has a creatinine clearance of 30 mL/min. Which pharmacokinetic adjustment is most appropriate?

    Answer: Keep the dose the same, extend the dosing interval

    Aminoglycosides are renally eliminated; in renal impairment, extending the dosing interval (not reducing the dose) maintains adequate peak concentrations while allowing drug clearance.

  2. Which pharmacokinetic/pharmacodynamic parameter best predicts the efficacy of vancomycin against MRSA?

    Answer: AUC/MIC ratio

    Current guidelines recommend targeting an AUC/MIC ratio of 400–600 for vancomycin, as this best correlates with clinical outcomes and minimizes nephrotoxicity.

  3. A patient on warfarin for atrial fibrillation is started on metronidazole for C. diff. What is the most important prescribing consideration?

    Answer: Metronidazole inhibits CYP2C9, increasing warfarin levels and bleeding risk

    Metronidazole inhibits CYP2C9, reducing warfarin metabolism and significantly increasing anticoagulant effect and bleeding risk; INR must be monitored closely.

  4. A patient with severe hepatic cirrhosis (Child-Pugh C) requires antibiotic therapy. Which agent requires the most significant dose reduction due to hepatic metabolism?

    Answer: Clindamycin

    Clindamycin is extensively hepatically metabolized and requires dose reduction in significant hepatic impairment, unlike renally cleared agents such as vancomycin or gentamicin.

  5. A pregnant woman in her first trimester develops a urinary tract infection. Which antibiotic should be avoided due to risk of fetal harm?

    Answer: Ciprofloxacin

    Fluoroquinolones (e.g., ciprofloxacin) are contraindicated in pregnancy due to evidence of fetal cartilage damage; beta-lactams and nitrofurantoin are safer alternatives.

  6. Which antibiotic class requires a loading dose strategy to achieve rapid therapeutic concentrations, particularly important in sepsis?

    Answer: Aminoglycosides with extended-interval dosing

    Extended-interval aminoglycoside dosing uses a high loading dose to achieve optimal peak/MIC ratios quickly, which is critical for concentration-dependent killing in sepsis.

  7. A patient with a creatinine clearance of 15 mL/min requires antibiotic therapy for a skin infection. Which agent is safest without dose adjustment?

    Answer: Doxycycline

    Doxycycline is primarily eliminated via the fecal-biliary route and does not require dose adjustment in renal impairment, unlike most antibiotics.