Dutasteride inhibits the conversion of testosterone to 5a-dihydrotestosterone (DHT). DHT is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5a-reductase, which exists as …

AVODART (dutasteride) is a synthetic 4-azasteroid compound that is a selective inhibitor of both the type 1 and type 2 isoforms of steroid 5a-reductase (5AR), an intracellular enzyme that converts testosterone to 5a-dihydrotestosterone (DHT).

Dutasteride is chemically designated as …