Methotrexate, available for over 40 years, is widely used to treat psoriasis and also used to treat cancer. In the 1970s, low-dose methotrexate was prescribed by many rheumatologists to treat rheumatoid arthritis when NSAIDs failed. Methotrexate works faster than other remittive drugs, often bringing improvement in weeks rather than months.
Methotrexate is an anti-metabolite, interfering with the utilization of folic acid. It is thought to inhibit immune system activity and reduce inflammation. It also may slow the rapid growth of cells in the synovial membrane which lines the joint.
Methotrexate can be given orally or as an injectable drug according to a strict dosage schedule. Along with the usual lesser side effects, long-term methotrexate use can result in liver damage. Routine liver function tests are required.
Methotrexate can be taken along with NSAIDs. Patients taking methotrexate are warned to avoid alcohol.
Sulfasalazine is a combination salicylate and antibiotic. It has been around since the 1940s, originally to treat patients with inflammatory bowel disease. At one time, it was used to treat rheumatoid arthritis but its use was limited because of concern over side effects. It was also used in clinical trials as an alternative to gold. There was a period of renewed interest in its use as a remittive agent without the toxicity problems of gold and penicillamine.
The mechanism of sulfasalazine is unknown though it has two potential actions, blocking inflammation and inhibiting the growth of bacteria. Sulfasalazine is available in tablet and liquid form. It should be avoided by people with allergies to sulfa drugs and/or aspirin and other salicylates. Common side effects include nausea, diarrhea, vomiting, and loss of appetite. More serious side effects are urine problems, blood diseases, and severe allergic reactions.
In choosing any particular drug to combat arthritis, you and your doctor must weigh the benefits and the risks of the treatment.
The Duke University Medical Center Book of Arthritis, David S. Pisetsky, M.D.