Methotrexate
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Warning
Methotrexate has rarely caused serious (sometimes fatal) side effects. This medication should be used only to treat cancer or severe diseases caused by an overactive immune system (such as psoriasis, rheumatoid arthritis).
Methotrexate has caused birth defects and death in unborn babies. Women must avoid becoming pregnant while taking this medication. Pregnant women who have psoriasis or rheumatoid arthritis must not use methotrexate. (See also Precautions section.)
If you have kidney problems or excess body water (ascites, pleural effusion), you must be closely monitored and your dose may be adjusted or stopped by your doctor.
Methotrexate (usually at high dosages) has rarely caused severe (sometimes fatal) blood/bone marrow problems (decreasing your body's ability to fight infections) and stomach/intestinal disease (such as bleeding) when used at the same time as non-steroidal anti-inflammatory drugs (NSAIDs such as indomethacin, ketoprofen). NSAIDs should not be used with high-dose methotrexate. Caution is advised if you also take aspirin. NSAIDs/aspirin may be used with low-dose methotrexate such as for the treatment of rheumatoid arthritis if directed by your doctor. If your doctor has told you to take low-dose aspirin to prevent heart attack or stroke (usually 81-162 milligrams a day), you should keep taking the aspirin unless your doctor tells you not to. Ask your doctor or pharmacist for more details on the safe use of these drugs (such as close monitoring by your doctor, keeping the same doses of NSAIDs).
In rare instances, this drug may also cause liver problems when it is used for long periods of time. If you are using methotrexate long term, a liver biopsy is usually recommended.
Methotrexate use has rarely caused serious (sometimes fatal) side effects, such as lung problems, lung infections (Pneumocystis jiroveci pneumonia), skin reactions, diarrhea, and mouth sores (ulcerative stomatitis). (See also Side Effects section.)
Lumps (tumors/abnormal growths) may very rarely appear during methotrexate use. The drug must be stopped and treatment may be needed. Tell your doctor right away if new lumps/growths occur.
When used to treat tumors, methotrexate sometimes causes side effects due to the rapid destruction of cancer cells (tumor lysis syndrome). To lower your risk, drink plenty of fluids unless your doctor directs you otherwise. Also, your doctor may prescribe an additional medication. Tell your doctor right away if you have symptoms such as irregular heartbeat, low back/side pain, signs of kidney problems (such as pink/bloody urine, change in the amount of urine, painful urination), or muscle spasms/weakness.
When this medication is used with radiation treatment, it may rarely increase the risk of tissue and bone damage. Discuss the risks and benefits of your treatment with your doctor.
Precautions
See also Warning section.
Before taking methotrexate, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, lung disease (such as pulmonary fibrosis), alcohol use, suppressed immune system, blood cell/bone marrow disorders, stomach/intestinal diseases (such as peptic ulcer, ulcerative colitis), any active infection (including chickenpox or recent exposure to it), folic acid deficiency.
Methotrexate can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.
Tell your health care professional that you are using methotrexate before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).
To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.
This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.
This medication can affect fertility in both males and females. Ask your doctor for more details.
Methotrexate must not be used during pregnancy. It may harm an unborn baby. Your doctor should order a pregnancy test before you start this medication. You should not become pregnant while using methotrexate. Women using this medication should ask about reliable forms of birth control during treatment and for 6 months after the last dose. Men using this medication should ask about reliable forms of birth control during treatment and for 3 months after the last dose. If you or your partner become pregnant, or think you are pregnant, talk to your doctor right away about the risks and benefits of this medication.
Since this drug can be absorbed through the skin and lungs and may harm an unborn baby, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.
Methotrexate passes into breast milk and may harm a nursing infant. Breastfeeding is not recommended while using this medication and for at least 1 week after the last dose. Consult your doctor before breastfeeding.
Side Effects
See also Warning section.
Nausea, vomiting, stomach pain, drowsiness, or dizziness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Temporary hair loss may occur. Normal hair growth should return after treatment has ended.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: mouth sores, diarrhea, signs of anemia (such as unusual tiredness, pale skin), signs of liver problems (such as nausea/vomiting that doesn't stop, dark urine, stomach/abdominal pain, yellowing eyes/skin), easy bruising/bleeding, black stools, enlarged glands/lymph nodes, bone pain, unusual pain and discoloration of the skin, signs of kidney problems (such as change in the amount of urine), dry cough, muscle weakness.
Get medical help right away if you have any very serious side effects, including: weakness on one side of the body, neck stiffness, severe headache, vision changes, irregular heartbeat, mental/mood changes, seizures.
This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills, cough).
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
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