finasteride
Last reviewed 01/2023
Finasteride is a steroid derivative that competitively inhibits 5 alpha-reductase, the enzyme that converts testosterone to its active metabolite, dihydrotestosterone.
Five alpha-reductase is present in highest concentration in the male reproductive tissues, the skin, especially overlying the genitalia, and the liver.
Finasteride reduces prostate volume, increases urinary flow rate and improves symptoms scores. However, it has not been shown to reduce the need for surgical treatment.
At the dose recommended for the treatment of benign prostatic hypertrophy, it does not inhibit the formation or action of any other steroid hormones. It is a more potent inhibitor of the type II form of 5 alpha-reductase.
The summary of product characteristics should be consulted before prescribing this drug.