Abiraterone 250 mg (Zytiga) is a brand-name prescription medication. It's used to treat two types of prostate cancer: Metastatic means the cancer has spread to other parts of the body. Both of these cancers are considered advanced. The word “castration” refers to the lowering of testosterone levels. Testosterone usually plays a role in stimulating prostate cancer growth. Prostate cancer is considered castration-resistant if the cancer continues to grow or spread even with therapy or surgery to lower testosterone levels. High-risk castration-sensitive cancer still responds to lowered testosterone levels but requires more aggressive treatment. Abiraterone 250 mg (Zytiga) contains the drug abiraterone acetate. It's a type of medication used in hormone therapy, which is a treatment that lowers the level of male hormones in the body. Reduced levels of male hormones, such as testosterone, help slow or stop the growth of prostate cancer cells. Abiraterone 250 mg (Zytiga) comes as an oral tablet that you take once a day. You'll take Abiraterone 250 mg (Zytiga) with a corticosteroid (prednisone) to reduce the risk of certain side effects. In some cases, you'll take Abiraterone 250 mg (Zytiga) and prednisone with a different type of hormone therapy to further lower testosterone levels.