Finasteride for benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH), a non-malignant enlargement of the prostate in aging men, can cause bothersome urinary symptoms (intermittency, weak stream, straining, urgency, frequency, incomplete emptying). Finasteride, a five-alpha reductase inhibitor (5ARI), blocks the conversion of testosterone to dihydrotestosterone, reduces prostate size, and is commonly used to treat symptoms associated with BPH.