[Effects of low dose methotrexate therapy in rheumatoid arthritis: a comparison of three different dosage regimens].

The effectiveness of methotrexate (MTX) in treatment of rheumatoid arthritis (RA) was evaluated by following the course of 232 cases. The number of cases in which MTX treatment was assessed as effective amounted to 149 (64.2%), and among these the number of cases in which the effect was excellent amounted to 59 (25.4%). As for the time required to achieve the therapeutic effect, effectiveness was evident within one month in most cases and the more prominent was the result, the shorter was the time required to achieve the effect. In analysis of it's effectiveness, no relationship to the patient's background such as morbidity period, the extent of inflammation, or the period of administration of anti-rheumatic drugs was observed and this drug seems promising for treatment of severe inflammation in cases of RA with prolonged course enabling application to a wide range of patients. Also, therapeutic effectiveness was observed in a group of elderly patients, who were more than 65 years old. However, in such cases, MTX should be administered carefully because of its reported strong adverse effects. Its effectiveness and adverse effects have been shown to be dose-dependent. Therefore, as the optimum dosage of MTX, it is recommended to administer a dose of 5.0 mg/week initially for an evaluation period of two months and in those cases in which no effect is observed, the dose is then increased to 7.5 mg/week.