A 42-year-old man with community-acquired pneumonia is started on azithromycin. After 3 days, he develops severe watery diarrhea with abdominal cramping and fever (38.9°C). Vital signs show HR 102/min, BP 128/76 mmHg, RR 18/min. Laboratory testing reveals WBC 13,800/μL and positive C. difficile toxin B in stool. Abdominal examination shows mild tenderness without peritoneal signs. Which mechanism explains this adverse effect of azithromycin?
- A)Hypersensitivity reaction to azithromycin metabolites
- B)Disruption of normal colonic flora allowing C. difficile overgrowthGABARITO
- C)Direct mucosal irritation by the macrolide
- D)Inhibition of intestinal motility leading to bacterial stasis
- E)Direct toxin production by azithromycin in the colon
Explicação
Macrolides like azithromycin disrupt normal colonic bacterial flora, allowing toxin-producing C. difficile to proliferate and cause pseudomembranous colitis. Ver explicação completa e trilha adaptativa →