Clinical effects of methotrexate on rheumatoid arthritis have been repeatedly confirmed by double blind controlled trials. Clinical activities definitely improved as early as 3 weeks of treatment. It was also shown that most of the patients resistant to gold, penicillamine or the other disease modifying drugs, responded to this drug. Although mechanisms of action of methotrexate on rheumatoid arthritis has not been clarified yet, both immunosuppressive and anti-inflammatory effects seems to be involved. Rare but severe side effects include bone marrow suppression, pneumonitis and liver fibrosis, while common but mild side effects are gastrointestinal symptoms and stomatitis.
Indication of methotrexate should be restricted only to severe cases, and careful monitoring of patients is essential during methotrexate administration.
