Methotrexate is a strong medicine used to treat several conditions. It belongs to a class of drugs called antimetabolites. It works by slowing down the production of cells. It also can suppress the immune system. This makes your immune system less active.

Methotrexate is used to treat:

  • Certain types of cancer.These include breast cancer, lung cancer, some cancers of the head and neck, leukemia, and certain types of lymphoma. It slows or stops the growth of the cancer cells.
  • Severe rheumatoid arthritis (RA). In this autoimmune disease, the body attacks its own joints. This causes pain, swelling, and loss of function in the joints. Methotrexate suppresses the immune system, which helps symptoms of RA.
  • Psoriasis.This is a skin disease that causes red, scaly, itchy patches to form on the body. Methotrexate slows the growth of skin cells. This keeps scales from forming. It’s used when other treatments don’t help.

Methotrexate (brand names: Rheumatrex and Trexall) also can be used to treat Crohn’s disease, multiple sclerosis, and other autoimmune diseases.

Path to improved health

Methotrexate is usually taken by mouth as a tablet. Sometimes it is given as an injection (a shot). The dosage and how often you take it depends on why you’re taking it. Some people take it on a rotating schedule of alternating days. People with RA or psoriasis often take it once a week. It’s a strong medicine, so it’s important to take it exactly as your doctor tells you. Some people have mistakenly taken it once a day instead of once a week. They experienced very serious side effects, including death. 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. It can take weeks or months before you feel the full effects of methotrexate. Don’t take more of it to try to speed up the process. Taking too much can cause harmful side effects.

Always talk to your doctor before stopping methotrexate.

Things to consider

Methotrexate may cause side effects. The most common include:

  • Dizziness.
  • Drowsiness.
  • Headache.
  • Loss of appetite.
  • Mouth sores.
  • Nausea (and sometimes vomiting).
  • Reddened eyes.
  • Swollen, tender gums.
  • Thinning hair.

Be sure to tell your doctor about any side effects you have. Some side effects of methotrexate can be serious. Call your doctor right away if you have:

  • A fever or feel as if you have the flu.
  • Diarrhea.
  • A nagging cough.
  • Shortness of breath.
  • Any unusual bruising or bleeding (including blood in the stool, or black, tarry stools).
  • Blurred vision or loss of vision.
  • Confusion.
  • Weakness or difficulty moving one or both sides of your body.

Methotrexate can cause other side effects, too. Call your doctor right away if you experience any unusual problems while taking this medicine.

What else should I know about taking methotrexate?

  • It’s important to keep every appointment with your doctor. He or she will need to watch the medicine’s effect on your body. They will also order blood tests to check your kidneys, liver, and blood production.
  • Don’t drink any alcohol, not even beer or wine. Drinking alcohol while you’re taking methotrexate can cause serious liver problems.
  • Don’t take medicine for pain or inflammation unless your doctor tells you it’s okay. This includes over-the-counter pain medicine such as NSAIDs. Examples of NSAIDS are ibuprofen (Advil) or naproxen (Aleve). Pain medicines can increase the effects of methotrexate, which can be bad for you.
  • Don’t take any vitamins, supplements, or herbal products without talking to your doctor first. These can cause serious damage to your body.
  • Don’t get any vaccines (shots) while you’re taking methotrexate. If you’ve stopped taking methotrexate, talk to your doctor to make sure that it’s okay to get a vaccine.
  • Taking methotrexate can make it easier for you to get an infection. Try to avoid people who are sick.

Methotrexate and pregnancy

Don’t take methotrexate if you or your partner are pregnant, trying to get pregnant, or breastfeeding. It can hurt your baby. Even touching or inhaling the dust from the tablet can allow the medicine to get into the body. Methotrexate goes into sperm, so it’s important that a man taking it doesn’t get his partner pregnant.

Whether you’re male or female, you must use birth control while taking methotrexate. You can take birth control pills, use a condom plus a spermicidal foam, or not have sex. After stopping methotrexate, women must continue to use birth control or not have sex until they have had at least 1 menstrual period after their last dose. Men should use birth control or not have sex for 3 months after their last dose of methotrexate.

If you have a young baby before taking methotrexate, don’t breastfeed him or her while taking this drug.

Questions to ask your doctor

  • Is methotrexate the best medicine for my condition?
  • What do I need to do before I start taking methotrexate?
  • How long will I need to take it?
  • What are the risks involved in taking it?
  • What are serious side effects I should watch for?
  • What happens if my partner or I become pregnant while taking methotrexate?