Tumor flare In the first one to two weeks of treatment, LHRH agonists cause an increase in testosterone production. This increase can cause tumor flare, a serious complication that may occur in men whose prostate cancer has metastasized. The initial testosterone increase can create a temporary increase in tumor growth and cause spinal compression, pain, paralysis, ureteral or bladder outlet obstruction, or a rise in PSA. If spinal metastasis or urinary obstruction is suspected, anti-androgens are given before LHRH analogs to prevent tumor flare. Total androgen blockade The testicles produce most, but not all, of the body’s androgens (male hormones). A small amount is produced by the adrenal glands, located on top of the kidneys. Drugs called anti-androgens block the action of the remaining male hormones. When anti-androgens are used in conjunction with LHRH analogs, the result is total androgen blockade. Experts differ about whether blocking these remaining androgens provides more effective treatment for prostate cancer than LHRH analogs or orchiectomy alone. The most common anti-androgen medications are flutamide (Eulexin), bicalutamide (Casodex) and nilutamide (Nilandron). All are oral medications administered in pill form. Casodex and Nilandron are taken once a day, Eulexin three times a day. Anti-androgens are expensive – hundreds of dollars a month – and may not be covered by insurance Side effects of anti-androgens Diarrhea, which occurs with Eulexin only, is the most significant side effect. Breast swelling and tenderness is a less common side effect of LHRH analogs in combination with anti-androgen therapy. Liver damage is a rare side effect of anti-androgens. Liver function is monitored through blood tests to make sure no damage is occurring. Nilandron may cause decreased night vision in some men. information last updated on October, 2006
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