Ovarian cancer medications are primarily used to treat this form of cancer. They also have other uses, such as managing specific types of lung cancer and breast cancer They generally work by targeting and killing cancer cells or stopping their growth. Common classes include alkylating agents, antimetabolites, and PARP inhibitors. Alkylating agents like cyclophosphamide and melphalan can be taken orally or given as injections. Antimetabolites, such as gemcitabine, are usually given as injections. PARP inhibitors like olaparib (Lynparza) are typically taken as oral pills.