FINSTAM

Finasteride is a competitive inhibitor of human 5α-reductase, an intracellular enzyme which metabolises testosterone into the more potent androgen, dihydrotestosterone (DHT). In benign prostatic hyperplasia (BPH), enlargement of the prostate gland is dependent upon the conversion of testosterone to DHT within the prostate. Finasteride is highly effective in reducing circulating and intraprostatic DHT. Finasteride has no affinity for the androgen receptor.

Tamsulosin binds selectively and competitively to post-synaptic α₁-adrenoreceptors, prevailingly their subtypes designated α_1A and α_1D. Thus relaxation of smooth muscles of the prostate and urethra is achieved, which leads to a reduction of tonus and an improvement of the urinary flow.