Abstract
Though disease-modifying antirheumatic drugs are now available for the treatment of rheumatoid arthritis, weekly low dose methotrexate (MTX, Rheumatrex®) is the most common treatment. MTX is a cancer chemotherapy agent whose adverse effects include nausea, stomatitis, bone marrow suppression, liver toxicity, and interstitial pneumonia. Since MTX is prescribed for outpatients, the detection and management of adverse effects is not easy. To investigate the occurrence and consequences of adverse effects due to MTX, we conducted a retrospective chart review study of 109 patients who received MTX in the past two years. We also examined the use of folic acid for the prevention and amelioration of adverse effects. Over the period of the study, 95 adverse events occurred in 62 patients and 2 of them were admitted for treatment. However through monthly follow up, it was possible to manage the adverse effects successfully in most of these patients. Concomitant folic acid supplementation not only reduced the toxic effects of MTX but also prevented their occurrence. We therefore feel that pharmacists should advise physicians to use folic acid for patients undergoing long-term therapy with MTX.
