Docetaxel Injection IP 120mg is a chemotherapy drug used to treat many types of cancer, including breast, ovarian, lung, prostate, and head and neck cancer. It is given intravenously (into a vein). It works by interfering with the growth of cancer cells. It is usually given in combination with other drugs. The most common side effects are low white blood cell count, hair loss, nausea, and vomiting.