Methotrexate is a DMARD, disease modifying anti-rheumatic drug when it is used in small doses (10-25 mg/week). In high doses it is used to treat some cancers. This is one of the most commonly prescribed medications for different types of the inflammatory arthritis (rheumatoid arthritis, psoriatic arthritis, arthritis related to connective tissue diseases) and often used as a steroid sparing medication while treating diseases requiring prolong courses of prednisone.

It works by suppressing the production of cells that are abundant in the swollen (inflamed) joints or other tissues.

The usual dose of methotrexate is 20-25 mg/week but sometimes it helps in even smaller doses. It can be given through the mouth or injection. The full effect of it is usually felt after approximately 3 months of use. Methotrexate is given together with a vitamin called folic acid. It can prevent some of the side effects of this medication.

There are situations when methotrexate is contraindicated. For example, pregnant, breasfeeding women or men and women who plan to have children. It should be stopped 3 months prior to the time when pregnancy is tried. It is also contraindicated in lung fibrosis, blood, liver, or advanced kidney diseases and with chronic infections. Regular use of alcohol and sulfa containing antibiotics should be avoided. Other medications used in rheumatology are safe in combination with methotrexate.

Common side effects of methotrexate are:

  • nausea;
  • diarrhea;
  • mouth sores;
  • tiredness after taking it.

Rare side effects are:

  • elevation of the liver enzymes and drop in the blood counts (this is why it is important to do regular blood work as per your doctor’s order);
  • shortness of breath, cough (medication should be stopped and your doctor notified);
  • with prolong use there might be a slight increase in the risk of lymphoma.

Your pharmacist will give you the full list of the side effects when you buy the medication. Please, advise your pharmacist about other medications you take.

Taking medication in the evening, before bed and switching to the injection method may prevent some of the common side effects.