Key takeaways
Azathioprine (Imuran, Azasan) and methotrexate (Trexall) are both medications used to treat rheumatoid arthritis, but they have different uses and belong to different drug classes. Azathioprine is an immunosuppressant that weakens your immune system to prevent it from attacking your joints or a transplanted kidney. Methotrexate, on the other hand, is an antimetabolite that can treat cancer at high doses and autoimmune conditions like rheumatoid arthritis and psoriasis at lower doses. Azathioprine is taken daily, while methotrexate is usually taken once a week. Both medications can increase your risk of infections and require regular blood tests, but methotrexate is also associated with serious side effects like liver damage and lung problems. Additionally, methotrexate is often taken with folic acid supplements to reduce side effects, which is not the case for azathioprine. Both medications are available in generic forms, making them more affordable.
