Pharmacodynamics and mechanism of action
BPH is a disease in which the prostate gland enlarges, causing symptoms such as frequent urination and difficulty urinating. Dutasteride belongs to the class of 5-alpha-reductase inhibitors and works by inhibiting the activity of the enzyme 5-alpha-reductase. This enzyme is responsible for converting testosterone into dihydrotestosterone (DHT), a hormone responsible for enlargement of the prostate. Inhibition of this enzyme decreases the formation of DHT, resulting in a reduction in the size of the prostate and significantly improving symptoms.
Dutasteride is rapidly and completely absorbed after oral administration, with maximum plasma concentrations reached within 2 to 3 hours. Dutasteride is approximately 99% bound to albumin. Dutasteride undergoes extensive hepatic metabolism mediated by the CYP3A4 and CYP3A5 enzymes and is excreted primarily in the feces. The plasma half-life is approximately 4-5 weeks.