What is the most common antibiotic associated with pseudomembranous colitis?

• A. Clindamycin
• B. Ciprofloxacin
• C. Piperacillin
• D. Amoxicillin

Answer: (A)

The most common antibiotic associated with pseudomembranous colitis is clindamycin. This condition is caused by the overgrowth of Clostridioides difficile (C. difficile) bacteria in the gut, which can occur when normal intestinal flora are disrupted by antibiotic use. Clindamycin is particularly notorious for this complication because it has a high propensity to disturb the gut microbiota, allowing for the growth of C. difficile.

While other antibiotics can also lead to pseudomembranous colitis, clindamycin is frequently cited in medical literature and clinical practice as the leading culprit. The mechanism involves the broad-spectrum activity of clindamycin against anaerobic bacteria, which may reduce beneficial bacteria that normally keep C. difficile in check, resulting in an imbalance. This imbalance allows C. difficile to proliferate and produce toxins that damage the intestinal lining, leading to pseudomembranous colitis.

The connection between clindamycin and this specific type of colitis is well-documented, making it the most commonly recognized antibiotic for this condition. Other antibiotics listed can also cause gastrointestinal issues, but they are less frequently associated with pseudomembranous colitis compared to clindamycin.