What is methotrexate?

Methotrexate interferes with the growth of certain cells of the body, especially cells that reproduce quickly, such as cancer cells, bone marrow cells, and skin cells.

Methotrexate is used to treat certain types of cancer of the breast, skin, head and neck, or lung. It is also used to treat severe psoriasis and and certain forms of rheumatoid arthritis.

Methotrexate is usually given after other medications have been tried without successful treatment of symptoms.

Methotrexate made also be used for purposes not listed in this medication guide.

Important Information

Methotrexate is usually not taken every day. You must use the correct dose for your condition. Some people have died after taking methotrexate every day by accident.

Do not use methotrexate to treat psoriasis or rheumatoid arthritis if you have low blood cell counts, a bone marrow disorder, weak immune system, liver disease (especially if caused by alcoholism), or if you are pregnant or breast-feeding.

Methotrexate can cause serious or life-threatening side effects. Tell your doctor if you have diarrhea, mouth sores, cough, shortness of breath, upper stomach pain, dark urine, numbness or tingling, muscle weakness, confusion, seizure, or skin rash that spreads and causes blistering and peeling.

Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, body aches).

Do not use methotrexate if you are pregnant or breast-feeding a baby.

Before taking this medicine

You should not use methotrexate if you are allergic to it. Methotrexate should not be used to treat psoriasis or rheumatoid arthritis if you have:

  • alcoholism, cirrhosis, or chronic liver disease;
  • low blood cell counts;
  • a weak immune system or bone marrow disorder; or
  • if you are pregnant or breast-feeding.

Methotrexate is sometimes used to treat cancer even when patients do have one of the conditions listed above. Your doctor will decide if this treatment is right for you.

Tell your doctor if you have:

  • kidney disease;
  • lung disease;
  • any type of infection; or
  • radiation treatments.

Methotrexate can harm an unborn baby or cause birth defects, whether the mother or father is taking this medicine.

  • If you are a woman, do not use methotrexate to treat psoriasis or rheumatoid arthritis if you are pregnant. You may need to have a negative pregnancy test before starting this treatment. Use an effective form of birth control while you are taking this medicine, and for 6 months after your last dose.
  • If you are a man, use a condom to keep from causing a pregnancy while you are using methotrexate. Continue using condoms for at least 3 months after your last dose.
  • Tell your doctor right away if a pregnancy occurs while either the mother or the father is taking methotrexate.

This medicine may affect fertility (ability to have children) in both men and women. However, it is important to use birth control to prevent pregnancy because methotrexate may harm the baby if a pregnancy does occur.

You should not breast-feed while using this medicine.

Do not give this medicine to a child without the advice of a doctor.

How should I take methotrexate?

Take methotrexate exactly as it was prescribed for you. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Methotrexate is sometimes taken once or twice per week and not every day. You must use the correct dose. Some people have died after taking methotrexate every day by accident. Ask your doctor or pharmacist if you have questions about your dose or how often to take it.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Methotrexate can be toxic to your organs, and may lower your blood cell counts. Your blood will need to be tested often, and you may need an occasional liver biopsy. Your cancer treatments may be delayed based on the results.

If you need to be sedated for dental work, tell your dentist you currently use this medicine.

Store tablets at room temperature away from moisture and heat.

Store the liquid medicine in the refrigerator, do not freeze.

You may also store the liquid at room temperature for up to 60 days.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose of methotrexate.

Get your prescription refilled before you run out of medicine completely.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of methotrexate can be fatal.