Am Fam Physician. 2000;62(7):1614
See related article on monitoring methotrexate.
What is methotrexate?
Methotrexate is a medicine that makes your immune system less active. Methotrexate is used to treat rheumatoid arthritis, psoriasis, Crohn's disease and other diseases that are associated with an immune system that is too active.
How do I take methotrexate?
Methotrexate is usually taken as an oral tablet. Sometimes it is given as an injection. It is a very strong medicine, so it is important to take it just as the doctor tells you. NEVER change the amount you take or the time of day you take this medicine. If you forget a dose, talk to your doctor before you take another dose. The doctor may want to tell you something else to do. If you take too much methotrexate, it can cause serious side effects.
What are the most common side effects of methotrexate?
Some common side effects are loss of appetite, nausea (and sometimes vomiting), diarrhea and mouth sores. Be sure to tell your doctor about any side effects you are having.
Call your doctor right away if you:
Have a fever or feel like you have the flu
Have diarrhea
Have a nagging cough
Feel short of breath
Have any unusual bruising or bleeding (e.g., black tarry stools).
What else should I remember about taking methotrexate?
It's important to keep every appointment with your doctor. Your doctor will need to watch the medicine's effect on your body. Your doctor will also order blood tests to check your kidneys, liver and blood production.
Don't drink any alcohol, even beer or wine. Drinking alcohol while you're taking methotrexate can cause liver problems.
Can I take methotrexate if I want to get pregnant or if I am breast-feeding?
No. Do not take methotrexate if you are pregnant, if you are trying to get pregnant, or if you are breast-feeding. Methotrexate can hurt your baby. If you are NOT pregnant, you must not get pregnant. You must use some kind of birth control (such as birth control pills or condoms plus spermicidal foam, or not having any sex). If, for any reason, your doctor has you stop taking methotrexate, you must keep using birth control for ONE month after your last dose of methotrexate.
I am a man and I want to get my partner pregnant. Can I take methotrexate?
No. Methotrexate goes into your sperm. You must use some kind of birth control (like a condom plus spermicidal foam, or not having any sex). You must keep using birth control for THREE months after your last dose of it.