What is the rare but serious side effect of topical clindamycin (antibiotic)?

Pseudomembranous Colitis: The Rare but Serious Side Effect of Topical Clindamycin

The most serious rare side effect of topical clindamycin is pseudomembranous colitis, which can result from Clostridium difficile overgrowth following disruption of normal intestinal flora. 1

Mechanism and Risk

• Topical clindamycin is absorbed through the skin surface, which can lead to systemic effects including disruption of normal gut microbiota 1
• This disruption allows Clostridium difficile to proliferate and produce toxins that cause colitis 2
• C. difficile produces toxins with cytopathic and hypersecretory effects on the colonic mucosa 3
• While rare with topical application, cases of diarrhea, bloody diarrhea, and colitis (including pseudomembranous colitis) have been reported 1

Clinical Presentation

• Symptoms include watery diarrhea, severe abdominal cramping, and possibly fever 1, 3
• May be associated with passage of blood and mucus 1
• Symptoms can develop up to several weeks following cessation of therapy 1
• In severe cases, toxic megacolon and acute peritonitis secondary to perforation of the colon can occur 3

Diagnostic Approach

• When significant diarrhea occurs, discontinue the medication immediately 1
• Endoscopic examination may reveal pseudomembranous colitis 1
• Stool culture for Clostridium difficile and stool assay for C. difficile toxin are helpful diagnostically 1, 4
• Lower gastrointestinal endoscopy is the only diagnostic test for pseudomembranous colitis, though it has limited sensitivity (51-55%) 4

Management

• Discontinue topical clindamycin immediately if diarrhea occurs 1
• For confirmed cases, treatment options include:
  • Oral vancomycin (500mg to 2g per day in 3-4 divided doses for 7-10 days) 1
  • Oral metronidazole for 10 days as an alternative to reduce risk of vancomycin resistance 4
• Avoid antiperistaltic agents such as opiates and diphenoxylate with atropine as they may prolong or worsen the condition 1
• Supportive care is essential during treatment 5

Risk Factors and Prevention

• History of regional enteritis, ulcerative colitis, or previous antibiotic-associated colitis increases risk 6, 2
• Clindamycin was the first antibiotic clearly associated with pseudomembranous colitis 3
• Consider alternative agents in patients with history of gastrointestinal disorders 2
• Prescribe topical clindamycin only when clearly indicated 5

Important Considerations

• The FDA label specifically warns about this risk in the warnings section for topical clindamycin 1
• Case reports have documented pseudomembranous colitis occurring after topical application of clindamycin for acne vulgaris 7
• Recurrence of symptoms occurs in 7-20% of patients and may require additional treatment approaches 4
• The American Academy of Dermatology guidelines note this as a contraindication for patients with history of antibiotic-associated colitis 6