A 67-year-old man with COPD presents with community-acquired pneumonia. Vital signs show HR 102, RR 22, SpO2 88% on 2L oxygen, BP 128/76, and temperature 38.5°C. Sputum culture reveals gram-negative rods; chest X-ray shows left lower lobe infiltrate. He is started on levofloxacin. On day 3, he develops severe watery diarrhea. C. difficile toxin assay is positive; no recent hospitalization documented. Which antimicrobial property predisposed him to this complication?

  1. A)Reduced gastric acid production increasing bacterial overgrowth
  2. B)Direct epithelial toxicity to the colonic mucosa
  3. C)Broad-spectrum coverage causing disruption of normal gut floraGABARITO
  4. D)Allergic reaction specific to gram-negative bacterial antigens
  5. E)Inhibition of intestinal peristalsis causing bacterial translocation

Explicação

Fluoroquinolones have broad-spectrum activity against both gram-positive and gram-negative organisms, including anaerobes. This broad coverage eliminates normal protective flora, allowing C. difficile proliferation and toxin production. Ver explicação completa e trilha adaptativa →

Fazer o diagnóstico grátis de USMLE