Understanding Arthritis and Chemotherapy Drugs
In cancer treatment, chemotherapy refers to particular drugs used to kill or slow the reproduction of rapidly multiplying cells.
In rheumatology, chemotherapy is designed to decrease the abnormal behavior of cells. The doses of medication used for rheumatic or autoimmune conditions are lower than the doses used for cancer treatment.
How Does Chemotherapy Treat Inflammatory and Autoimmune Diseases?
In many rheumatic diseases, inflammation causes damage to parts of the body, such as what happens to the joints in rheumatoid arthritis. In many cases, inflammation results from autoimmunity, a malfunction of the immune system where one's own tissues or organs are not recognized as such and are attacked by the body's immune system.
Chemotherapy slows cell reproduction and decreases certain products made by these cells, and therefore may help people with certain inflammatory and autoimmune diseases. Because of the suppressive effect of chemotherapy on autoimmunity, these drugs are sometimes called immunosuppressive drugs.
What Chemotherapy Drugs Do Doctors Use?
Although there are many chemotherapy drugs, only three have widespread use in treating rheumatic diseases today. These are:
- methotrexate (Rheumatrex)
- azathioprine (Imuran)
- cyclophosphamide (Cytoxan)
Methotrexate
Methotrexate is the chemotherapeutic drug most widely used by rheumatologists for two main reasons. It is effective in treating rheumatoid arthritis and certain other rheumatic diseases (especially polymyositis and certain types of vasculitis or inflammation of blood vessels), and it is relatively safe.
Most patients can take methotrexate by mouth in a single, weekly dose. Some patients prefer to take it as an injection once a week.
Azathioprine
Azathioprine has been used for many years as an immunosuppressive drug to prevent rejection in patients receiving kidney transplants. It is also used to suppress the abnormal immune response in some patients with vasculitis, systemic lupus erythematosus, rheumatoid arthritis, and vasculitis. Azathioprine has been linked to lymphoma, a cancer of the lymph nodes.
Cyclophosphamide
Cyclophosphamide is considerably more powerful and toxic than methotrexate and azathioprine. It is used to treat the most aggressive and dangerous rheumatic diseases, such as severe lupus and some forms of vasculitis.
Cyclophosphamide directly attacks rapidly reproducing cells such as those in the immune system. Resting cells, that are not multiplying, can be affected if there is enough drug present.
Cyclophosphamide is taken either by mouth or by injection.
WebMD Medical Reference

