Which pharmacologic agent is used to enzymatically break down penile plaque in Peyronie’s disease?

• A. Paclitaxel
• B. Insulin
• C. Collagenase clostridium histolyticum
• D. Amoxicillin

Answer: (C)

Peyronie’s disease involves a fibrous plaque in the penis that is rich in collagen, causing curvature. The therapeutic idea here is to chemically weaken that plaque by breaking down its collagen fibers. Collagenase clostridium histolyticum is an enzyme that directly cleaves collagen, allowing the plaque to soften and the penis to straighten more with erections. It is given by intralesional injections into the plaque in a treatment course, sometimes with penile modeling, to reduce curvature and improve function. The other choices don’t have this mechanism: Paclitaxel is a cancer drug that disrupts cell division, insulin regulates blood sugar, and amoxicillin is an antibiotic.