What is a key use and major adverse effect of clindamycin in anaerobic infections?

• A. Useful for anaerobes in intra-abdominal and gynecologic infections; major adverse effect is C. difficile colitis.
• B. Primarily treats MRSA skin infections; major adverse effect is nephrotoxicity.
• C. Broadly used for viral infections; major adverse effect is hepatotoxicity.
• D. Not effective against anaerobes; major adverse effect is QT prolongation.

Answer: (A)

Clindamycin is particularly useful when anaerobic bacteria drive the infection, because it has strong activity against anaerobes such as Bacteroides species and anaerobic streptococci and penetrates into tissues and abscesses. This makes it a good choice for infections where anaerobes are key players, like intra-abdominal and gynecologic infections. A major adverse effect to watch for with clindamycin is antibiotic-associated colitis due to Clostridioides difficile, which can cause severe diarrhea and colitis even after short courses.

Other ideas in the choices don’t fit as well: clindamycin isn’t a primary agent for MRSA skin infections with nephrotoxicity as the main risk, it’s not used for viral infections, and clindamycin is active against anaerobes, so saying it’s not effective against them would be incorrect.