Disease-modifying drugs act on the immune system to slow the progression of rheumatoid arthritis. This is why they are called "disease-modifying." Many different drugs can be used as DMARDs in the treatment of RA, but some are used more often than others.
The rheumatoid factor test is a commonly ordered test to help diagnose rheumatoid arthritis. This test measures rheumatoid factor, which is an antibody in the blood that's present in many people with RA. In fact, the rheumatoid factor blood test is eventually positive in 70% to 80% of people with RA, although in early arthritis the percentage may be much smaller. Rheumatoid factor may also be elevated in other autoimmune diseases besides RA.
Methotrexate is the most commonly used DMARD. This is because it has been shown to work as well or better than any other single medicine. It is also relatively inexpensive and generally safe. Like other DMARDs, methotrexate has side effects; it can cause rash and stomach upset, can be toxic to the liver or bone marrow, and can cause birth defects. In rare cases, it can also cause shortness of breath. Regular blood work is necessary when taking methotrexate. Taking folic acid helps reduce some of the side effects. Methotrexate's biggest advantage could be that it has been shown to be safe to take for long periods of time and can even be used in children.
Plaquenil(hydroxychloroquine) and Azulfidine(sulfasalazine) are used for mild rheumatoid arthritis. They are not as powerful as other DMARDs, but they usually cause fewer side effects. In rare cases, Plaquenil can adversely affect the eyes, and patients taking this medicine should be seen by an ophthalmologist at least once a year.
Minocin (minocycline) is an antibiotic. But it may help RA by stopping inflammation. It can take several months to start working and up to a year before the full effects are known. When taken for long periods, minocycline can cause discoloration of the skin.
Arava(leflunomide) works about as well as methotrexate and can work even better in combination with it. The side effects are similar to methotrexate. Sometimes Arava causes diarrhea and can't be used. Since Arava is known to cause harm to a fetus, women must take special precautions to not get pregnant while on it.