Israel Medical Association Journal

Methotrexate, a folate analog antimetabolite, is one of the oldest cytotoxic drugs still in use. It is active against a variety of malignancies including bladder and breast cancer, head and neck tumors, gestational choriocarcinoma, osteogenic sarcoma, lymphomas, and leukemias.

Methotrexate is given mostly intravenously (IV), usually at standard doses (milligrams). It can also be delivered in much higher doses (grams), which is known as high-dose methotrexate (HDMTX). The intrathecal (IT) route is used particularly in children with acute lymphoblastic leukemia (ALL) and in adults with meningeal carcinomatosis. The drug may be administered orally as well, mainly in non-oncological conditions such as rheumatoid arthritis and other autoimmune diseases.

Docetaxel (Taxotere®), obtained from the European yew Taxus baccata, is a widely used chemotherapeutic agent active against a variety of solid tumors including breast, lung, ovarian, gastric, head and neck, and prostate cancers. The drug is administered intravenously on a weekly or three-weekly schedule. Its main side effects include myelosuppression, fatigue, myalgias, arthralgias, fluid retention, peripheral neuropathy, paronychia, and lacrimation [1]. Myositis, however, has rarely been reported.

We describe a breast cancer patient who developed severe acute myositis while on treatment with docetaxel.