These drugs have been approved for use as hormone therapy in patients with advanced prostate cancer. Luteinizing hormone-releasing hormone (LHRH) antagonists lower testosterone levels more quickly than LHRH analogs. In addition, they don't cause a tumor flare (temporary rise in testosterone levels) as do LHRH analogs. Degarelix (Firmagon) is a LHRH antagonist used to treat advanced prostate cancer. It has been shown to decrease the progression of disease, but further trials are needed to look at long-term outcomes. It is fairly well tolerated with common side effects being local injection site problems and increased liver enzymes.