Antibiotic-associated diarrhea

Differential Diagnosis

• Clostridioides difficile-associated diarrhea (10 to 20%)
• Other microbes:
  • Clostridium perfringens type A, weeks after therapy
  • Methicillin-resistant Staphylococcus aureus
  • Salmonella species, particularly drug-resistant Salmonella newport
  • Possibly Candida albicans overgrowth
• Direct effects on intestinal tract
  • Erythromycin and clavulanate cause increased motility
  • Penicillins may rarely cause an acute, hemorrhagic segmental colitis, usually within 4 days of therapy
• Effects on the fecal microbiota
  • Decreased metabolism of carbohydrates, leading to osmotic diarrhea
  • Decreased metabolism of primary bile acids, leading to secretory diarrhea
• Concomitant use of laxatives, antacids, contrast, lactose- or sorbitol-containing products, NSAIDs, antiarrhythmic drugs, and cholinergic drugs

Management

• Treat the underlying cause

Prevention

• Research has mostly focussed on the use of probiotics to prevent antibiotic-associated diarrhea
• A systematic review has shown that probiotics decrease antibiotic-associated diarrhea from 18% to 8%1
  • No harms found, except rare bacteremia in severely immunocompromised patients or those with active Crohn disease
  • Lactobacillus rhamnosus and Saccharomyces boulardii appear to be more effective than Lactobacillus acidophilus plus Bifidobacterium animalis lactis

Further Reading

• Mechanisms and Management of Antibiotic-Associated Diarrhea. Clin Infect Dis. 1998;27(4):702-710. doi: 10.1086/514958