These prostate cancer drugs work by blocking the effect of testosterone in the body. Antiandrogens are sometimes used in addition to orchiectomy or luteinizing hormone-releasing hormone (LHRH) analogs. This is because of the fact that the other forms of hormone therapy remove about 90% of testosterone circulating in the body. Antiandrogens may help block the remaining 10% of circulating testosterone. Using antiandrogens with another form of hormone therapy is called combined androgen blockade (CAB), or total androgen ablation. Antiandrogens may also be used to combat the symptoms of flare (temporary rise in testosterone that occurs with the use of LHRH agonists). Some doctors prescribe antiandrogens alone rather than with orchiectomy or LHRH analogs. Available antiandrogens include abiraterone acetate (Zytiga), biclutamide (Casodex), enzalutamide (Xtandi), flutamide (Eulexin), and nilutamide (Nilandron). Patients take antiandrogens as pills. Diarrhea is the primary side effect when antiandrogens are used as part of combination therapy. Less likely side effects include nausea, liver problems, and fatigue. When antiandrogens are used alone they may cause a reduction in sex drive and impotence.