Class: Chemotherapy
Generic Name: Methotrexate (meth-oh-TRECKS-ate), Amethopterin, Methotrexate Sodium, MTX
Trade Name: Rheumatrex®, TrexallTM
How is this drug used? Methotrexate is FDA approved for the following cancers: gestational choriocarcinoma, chorioadenoma destruens and hydatidiform mole, acute lymphocytic leukemia, meningeal leukemia, breast cancer, epidermoid cancers of the head and neck, advanced mycosis fungoides, lung cancer, advanced non-Hodgkin’s lymphomas, and osteosarcoma. It is important for patients to remember that physicians have the ability to prescribe medication for conditions other than those for which the drug has been approved by the FDA. Patients who have received a prescription of this drug for a condition other than which it is approved may wish to discuss this issue with their physician.
What is the mechanism of action? Methotrexate belongs to a group of agents classified as antimetabolites. Antimetabolites produce their anti-cancer effects by inhibiting the ability of a cell to produce or repair DNA, thereby making the cell unable to replicate or repair itself and ultimately causing cellular death.
How is methotrexate given (administered)? Methotrexate may be administered into a vein (intravenous), into a muscle (intramuscular), into the spinal fluid (intrathecal or intraventricular), or by mouth as a pill. The dose and method of administration depend on several factors, including the condition being treated, the size of the patient, the particular regimen being used and the overall health of the patient. Patients who are treated with high doses of methotrexate will often receive hydration in the form of intravenous fluids, prior to and after administration of the drug.
How are patients monitored? Patients will usually have scheduled meetings with their healthcare provider while they are being treated with methotrexate. Typically, blood will be drawn to check levels of blood cells and to monitor functions of some organ systems, such as the kidneys or liver. Patients may also undergo physical examinations, scans or other measures to assess side effects and response to therapy.
In addition, patients will be monitored for inflammation of the membrane surrounding the brain and spinal column (meninges), if they receive methotrexate intrathecally or intraventricularly. Inflammation of the meninges may cause stiff neck, (?seizures), vomiting, fever, back pain and severe headache, which typically occur immediately following administration of the drug. Patients will also be monitored for side effects affecting the central nervous system, which may produce paralysis of the arms and legs, difficulty with speaking, confusion, sleepiness, seizures, or coma. These symptoms may occur up to approximately 6 days following treatment, so patients experiencing any of these symptoms should contact their healthcare provider immediately.
What are the common (occur in 30% or more of patients) side effects of treatment with methotrexate?
• Low white blood cell levels – increases the risk of infection
• Low red blood cell levels – increases the risk of anemia
• Low platelet levels – increases the risk of bleeding
• Mouth sores
• Loss of appetite
• Nausea and vomiting
What are the less common (occur in 10% to 29% of patients) side effects of treatment with methotrexate?
• Kidney problems – abnormalities will be detected on blood draws, swelling of ankles and feet may occur, difficulty in urination may occur
• Diarrhea
• Hair loss
• Irritation of the eye
• Abnormalities of liver function levels, as detected by blood tests
• Liver damage (generally only after prolonged use)
• Infertility
• Darkening of skin at previous sites of radiation
• Skin rash, itching
• Reddening of skin, sensitivity to sunlight
• Fatigue
• Chills and fever
This is not a complete list of side effects. Some patients may experience other side effects that are not listed here. Patients may wish to discuss with their physician the other less common side effects of this drug, some of which may be serious.
Some side effects may require medical attention. Other side effects do not require medical attention and may go away during treatment. Patients should check with their physician about any side effects that continue or are bothersome.
What can patients do to help alleviate or prevent discomfort and side effects?
• Pay careful attention to the physician’s instructions and inform the physician of any side effects.
• Maintain adequate rest and nutrition.
• Wear sunscreen and protective clothing and try to minimize sun exposure.
• Drink plenty of fluids. (Patients should ask their physician about the amount of liquid to consume during a day.)
• If possible, avoid large crowds or people who are sick or not feeling well, as this drug may leave some patients susceptible to infection.
• Wash hands often to reduce the risk of infection.
• Eat small meals frequently to help alleviate nausea.
• If patients have been prescribed an anti-nausea medication, they should be sure to take the prescribed doses.
• Avoid activities that may cause injury or bruising.
• Use a soft toothbrush and an electric razor to prevent cuts on the mouth or skin.
• For mouth sores, patients should rinse their mouth three times a day with a salt and soda solution (8 ounces of water mixed with ½ to 1 tsp baking soda and/or ½ to 1 tsp salt) and brush their teeth with a soft toothbrush to help prevent the development of mouth sores.
Are there any special precautions patients should be aware of before starting treatment?
• Patients should inform their physician if they are pregnant, breastfeeding or planning a family in the near future. This drug may cause birth defects. It is important to use some kind of birth control while undergoing treatment. Also, patients may want to talk to their physician if they are considering having children in the future, since some drugs may cause fertility problems.
• It is important that patients inform their physician of any pre-existing conditions (chicken pox, heart disease, kidney disease, liver disease, lung disease, etc.) as they may worsen with this drug.
• Patients should inform their physician of any other medication they are taking (whether prescription or over-the-counter, including vitamins, herbs, etc.) as they may interfere with treatment.
• Patients should check with their physician before starting any new drug or nutritional supplement.
• Patients should inform their physician of any known drug or food allergies or any reactions to medications they have experienced in the past.
• If an oral dose is missed, do not double up on doses. Patients should contact their doctor in this event.
• Keep tablets out of reach of children and return to the pharmacy for safe disposal if treatment is terminated.
When should patients notify their physician?
• Swelling of feet or ankles
• Sudden weight gain
• Little or no urine output for 8 – 12 hours
• Signs of inflammation of the meninges – severe headache, vomiting, stiff neck, seizures, fever
• Signs of central nervous system toxicity – paralysis of the arms/legs, difficulty speaking, seizures, coma, drowsiness, confusion, dizziness
• Flu or cold-like symptoms – fever, sore throat, cough, chills
• Signs of infection – redness, swelling, pus, tenderness, painful or frequent urination
• Persistent or severe fatigue
• Unexplained or pronounced bleeding (nosebleeds, bruising, blood in the urine, black tarry stools, etc.)
• Persistent or extreme nausea or vomiting
• Mouth sores
• Persistent or extreme diarrhea
• Acute joint pain
• Dry, non productive cough, shortness of breath,
• Skin rash, itching, hives, wheezing, difficulty breathing
• Yellowing of skin or eyes
• Blurred vision
What is a package insert?
A package insert is required by the FDA and contains a summary of the essential scientific information needed for the safe and effective use of the drug for healthcare providers and consumers. A package insert typically includes information regarding specific indications, administration schedules, dosing, side effects, contraindications, results from some clinical trials, chemical structure, pharmacokinetics and metabolism of the specific drug. By carefully reviewing the package insert, you will get the most complete and current information about how to safely use this drug. If you do not have the package insert for the drug you are using, your pharmacist or physician may be able to provide you with a copy.
Copyright © 2010 CancerConnect Last updated 07/10.
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