Breast cancer medications can treat many forms of breast cancer. These medications also have other uses, such as treating certain hormone-related health conditions. They work in various ways, including blocking hormones that fuel cancer growth and killing cancer cells. Common classes include aromatase inhibitors, antimetabolites, and selective estrogen receptor modulators (SERMs). Aromatase inhibitors like anastrozole (Arimidex) are usually taken as oral pills. Antimetabolites, such as capecitabine (Xeloda) and fluorouracil, can be taken orally or as injections. SERMs like tamoxifen (Soltamox) are typically taken as oral pills. Several other classes are also available.