LHRH agonists and antagonists can stop the testicles from making androgens, but other cells in the body, including prostate cancer cells themselves, can still make small amounts, which can fuel cancer growth. Abiraterone (Zytiga) blocks an enzyme called CYP17, which helps stop these cells from making androgens.
Abiraterone can be used in men with advanced castrate-resistant prostate cancer. (cancer that is still growing despite low testosterone levels from an LHRH agonist, LHRH antagonist, or orchiectomy).
This drug is taken as pills every day. It doesn’t stop the testicles from making testosterone, so men who haven’t had an orchiectomy need to continue treatment with an LHRH agonist or antagonist. Because abiraterone also lowers the level of some other hormones in the body, prednisone (a cortisone-like drug) needs to be taken during treatment as well to avoid certain side effects.