Flutamide (FTM)

Flutamide is an oral, non-steroidal antiandrogen drug primarily used to treat prostate cancer. It competes with testosterone and its powerful metabolite, dihydrotestosterone (DHT) for binding to androgen receptors in the prostate gland. Flutamide has been largely replaced by a newer member of this class, bicalutamide, due to a better side-effect profile. Normally administered are analogues of GnRH, such as leuprolide or goserelin. Although they stimulate the same receptors that GnRH does, since they are present continuously and not in a pulsatile manner, they serve to inhibit the pituitary and therefore block the whole chain. However, they initially cause a surge in activity; this is not solely a theoretical risk but may cause the cancer to flare. Flutamide was initially used at the beginning of GnRH-analogue therapy to block this surge, and it and other nonsteroidal anti-androgens continue in this use.