Table of Contents

Chapter 6: Using Hormone Therapy

ii. Blocking Testosterone Action

Once testosterone is released from the testicles, it is converted into dihydrotestosterone (DHT). DHT, in turn, crosses into the nucleus or central part of the cells and promotes the synthesis of PSA and the growth of prostate cancer cells.

Antiandrogens such as bicalutamide (Casodex), flutamide (Eulexin), and nilutamide (Nilandron), block DHT action in the cell and can therefore play an important role in preventing testosterone action. Although these agents can be used on their own, as we’ll discuss in more detail below, they’re more commonly used in combination with the LHRH agonists. Also, as we’ll discuss below, adding or subtracting these agents is a useful strategy in men whose PSA levels are rising as they start to lose their sensitivity to hormone therapy.