Antimicrobials USMLE Step 1 Practice Question
A 45-year-old woman with a history of rash following amoxicillin 10 years ago presents to the emergency department with a 3-day history of productive cough with purulent sputum, pleuritic chest pain, and dyspnea. She denies prior episodes of urticaria, angioedema, bronchospasm, or anaphylaxis. Vital signs: BP 128/82 mmHg, HR 102/min, RR 22/min, temperature 38.5°C, SpO2 94% on room air. Examination reveals decreased breath sounds and dullness to percussion at the left lung base. Laboratory findings show WBC 14,200/mm³ with left shift. Chest radiograph shows left lower lobe consolidation. Beta-lactam skin testing is negative for immediate-type hypersensitivity reactions to penicillins and negative to third-generation cephalosporins. Which of the following is the most appropriate empiric antibiotic for community-acquired pneumonia in this patient?
Answer choices
- AAmoxicillin-clavulanate
- BCefazolin
- CCeftriaxoneCorrect answer
- DClarithromycin
- EPiperacillin-tazobactam
- FFluoroquinolone monotherapy
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