Methotrexate works by altering the immune system to decrease the activity of immune cells called T lymphocytes. It is a pill that you take by mouth or an injection (shot) that is done one time a week. It can take three to six months for your skin to improve.

Side effects of methotrexate

  • Upset stomach
  • Fatigue (feeling very tired)
  • Cold or flu-like symptoms
  • Mouth sores
  • Low blood counts
  • Higher risk of infections

Rare but serious side effects of methotrexate

  • Liver damage
  • Severe infections
  • Lymphoma
  • Lung disease called pneumonitis

Call your doctor if you have any of the above side effects.

Take an over-the-counter folic acid supplement on the six days of the week that you do not take methotrexate. The folic acid will help stop many of the above side-effects.

Alcohol and methotrexate

Do not drink alcohol while taking methotrexate.

Last reviewed: 
August 2018

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