Methotrexate is a chemotherapy drug used to treat many different types of cancer, as well as some non-cancer diseases. As with most chemotherapy drugs, the benefits, as well as the side effects, can be significant. With sufficient knowledge about the drug, patients can work with a doctor to ensure the benefits outweigh the side effects.
Drug Classification
Chemotherapy drugs are classified according to the way in which they cause cell death. Each class of chemotherapy drug causes cell death during a different phase of the cell's growth cycle. According to the American Cancer Society, methotrexate is classified as an antimetabolite and inhibits cell growth in the S phase. The S phase occurs close to the end of the cell cycle and involves growth and synthesis of DNA. Antimetabolites interfere with DNA growth of both normal cells and cancer cells. Side effects occur because the antimetabolites cannot differentiate between a normal cell and a cancer cell. Methotrexate is used to treat a variety of cancers, as well as some non-cancerous diseases. Methotrexate is effective against lymphoma; leukemia; and head and neck, breast, colon, lung and ovarian cancers. Methotrexate may be used alone or in combination with other drugs to treat these and other cancers.
Correct Use and Dosing
Methotrexate can be given by a nurse through an intravenous route in a hospital setting, or can be taken in pill form at home. Pregnant or breastfeeding women should not take methotrexate because it is very toxic to a fetus or infant, notes PDRhealth. The doctor should be informed if future pregnancy is desired because this drug may cause sterility. A doctor will identify the appropriate dose and schedule of methotrexate based on various factors. If methotrexate is taken at home it is very important to maintain the correct dosing schedule and avoid missing or doubling doses. The medication must be kept at room temperature and away from children.
Potential Side Effects
Because methotrexate cannot differentiate between healthy cells and cancer cells, it destroys both types of cells creating various side effects. According to the Mayo Clinic, some side effects may be mild while others can be more severe. Mild side effects include decreased appetite, sensitivity to sunlight, nausea with possible vomiting, acne and itchy skin. More distressing side effects include blood in urine, stool or vomit; confusion; blurred vision; lower extremity swelling; diarrhea and shortness of breath. All side effects should be reported to a doctor. Methotrexate may alter components of the blood, including platelets and white blood cells. Platelets are responsible for clotting the blood and white blood cells are responsible for fighting infection. If any unusual bleeding is noticed it may mean the platelet count is low. If fever or chills develop, it may mean the white blood cell count is low. Signs of bleeding or infection must be reported to a doctor immediately to prevent a potentially serious situation. Although taking a chemotherapy drug such as methotrexate may seem overwhelming, with education and frequent contact with a health care team, the experience can be positive.
