Abstract
Post-marketing surveillance was performed to clarify the condition of actual use of mizoribine in treating patients with rheumatoid arthritis, collect information about its safety and efficacy under the condition of actual use and promote its proper use. The safety analysis population included 3,325 patients who started to receive mizoribine between October 2008 and October 2010. Their mean age was 66.2±12.5 years and those over 65 years and those over 75 years accounted for 61.1% and 28.4%, respectively. Complications were detected in 59.3% of the subjects. A total of 330 subjects experienced 392 episodes of adverse drug reactions. The incidence of adverse drug reactions was 9.92% and that of serious adverse drug reactions was 1.32%. Based on the European League Against Rheumatism (EULAR) response criteria, the efficacy of mizoribine was rated and the treatment responses observed 24 weeks later were classified as follows: good response (13.4%), moderate response (32.6%), and no response (54.0%). Although there was no difference between the subjects over 65 years and those under 65 years in terms of the incidence of adverse drug reactions and efficacy of mizoribine, the incidence of serious adverse drug reactions in the subjects over 65 years was significantly higher than that in the subjects under 65 years. Mizoribine was administered to high-risk patients including the elderly and those with complications in the post-marketing surveillance. As mizoribine could be administered in a relatively effective and safe manner, this drug could be a treatment option in these patients.
