Which antibiotic is most commonly associated with GI upset and pseudomembranous colitis?

Which antibiotic is most commonly associated with GI upset and pseudomembranous colitis?

• A. Amoxicillin
• B. Erythromycin
• C. Tetracycline
• D. Clindamycin

Answer: (D)

Disruption of the normal gut flora by antibiotics can let Clostridioides difficile overgrow and release toxins that inflame and damage the colon, causing antibiotic-associated diarrhea and, in some cases, pseudomembranous colitis. Clindamycin is the classic culprit because it profoundly reduces anaerobic bacteria in the gut, creating an environment where C. difficile can thrive. The toxins produced by this organism (toxin A and toxin B) drive the inflammation and mucosal injury, leading to pseudomembranes and significant GI symptoms. Other antibiotics like amoxicillin, erythromycin, or tetracycline can cause GI upset, but they are less specifically linked to pseudomembranous colitis, so the association is strongest with clindamycin.

Disruption of the normal gut flora by antibiotics can let Clostridioides difficile overgrow and release toxins that inflame and damage the colon, causing antibiotic-associated diarrhea and, in some cases, pseudomembranous colitis. Clindamycin is the classic culprit because it profoundly reduces anaerobic bacteria in the gut, creating an environment where C. difficile can thrive. The toxins produced by this organism (toxin A and toxin B) drive the inflammation and mucosal injury, leading to pseudomembranes and significant GI symptoms. Other antibiotics like amoxicillin, erythromycin, or tetracycline can cause GI upset, but they are less specifically linked to pseudomembranous colitis, so the association is strongest with clindamycin.