We aim to examine changes in usage of nonbiologic, disease-modifying antirheumatic drugs (DMARDs) and evaluate their continuation rates in Japan.
We analyzed DMARD treatment data for 3,734 patients with rheumatoid arthritis (RA) from 1998 to 2009 at Juntendo Hospital in Tokyo, Japan. The DMARD usage rate per month was determined to evaluate RA treatment history in the last decade. We also evaluated continuation rates of nonbiologic DMARDs in single and combination therapies and number of nonbiologic DMARD combination therapies used in each patient.
We found that nonbiologic DMARD usage has dramatically changed in the last decade, with the most commonly used DMARD shifting from bucillamine to methotrexate (MTX). MTX showed the highest continuation rate; however, much lower continuation rate was observed when used alone rather than in combination treatments. Further, MTX was also used in the highest number of different combination therapies for a particular patient.
These findings indicate that single MTX treatment may be unable to keep patients in clinical remission or lower disease activity compared with several combination therapies. Recent change in permitted maximum dosage of MTX from 8 to 16 mg/week may improve its efficacy and continuation rate in treating Japanese RA patients.