What is Methotrexate?
Methotrexate is a drug used to treat rheumatoid arthritis (RA) and and other inflammatory conditions. Nearly 60% of all rheumatoid arthritis patients are currently on or have been on methotrexate. Methotrexate is recommended as the first treatment for RA by the American College of Rheumatology.
How do I take it?
Methotrexate is taken ONCE A WEEK. You will choose a day of the week, for example Saturday. You will then take your methotrexate every Saturday. The injection is available in 25mg/ml or 50mg/2ml vials. The usual dose is 7.5mg to 25mg per week. Methotrexate may be injected just under the skin or intramuscularly. Follow your rheumatologist’s directions. Do not take more or less medicine than ordered. You should also take 1mg of folate (folic acid) each day. Your rheumatologist will prescribe the folic acid. This will help prevent side effects.
What about side effects?
Methotrexate can cause mouth ulcers in a few patients, in the beginning of treatment. This should go away with time. Another possible side effect is nausea and vomiting. Methotrexate can also cause hair thinning or hair loss. In rare cases some people may develop lung problems. Call the rheumatologist’s office if any of the side effects are bothersome.
Methotrexate can cause mild liver irritation. Please tell your doctor if you have a history of any alcohol abuse, hepatitis, yellow jaundice, or liver disease. While on methotrexate you should limit yourself to 2 alcoholic beverages per week. Blood work will be done every 4-12 weeks to check your liver function. This blood work will also include a complete blood count (CBC) since methotrexate can also cause a decrease in blood counts. This blood work is very important. It allows the rheumatologist to make timely changes to your dose of methotrexate if there is ever problem.
Methotrexate is known to cause birth defects in the children of both men and women taking this drug. If you are pregnant considering having a child, or nursing, discuss this with your rheumatologist before beginning this medication. You must use an effective form of birth control while taking methotrexate and for at least 3 months after the methotrexate is stopped. Your rheumatologist or nurse can give you additional guidance.
What about other medications?
When you are taking methotrexate, it is very important that your doctors know if you are taking any other medicine. This includes prescription and non-prescription medicines as well as birth control pills, vitamins, and herbal supplements. Methotrexate can be taken with other medications. You should not take methotrexate while taking antibiotics containing trimethoprim-sulfa (Bactrim®, Sulfatrim®, etc…). If you are prescribed one of these medications for an infection, do not take your methotrexate that week.
What else should I know?
The effects of methotrexate on joint swelling and tenderness can be seen from 4 to 8 weeks. Store the methotrexate at room temperature (25⁰C or 77⁰F) and protect from light.
Always call your health care provider if you have any questions or concerns.
