Long-term use of mizoribine in rheumatoid arthritis patients on hemodialysis

Abstract Small doses of mizoribine (MZR) were administered to five rheumatoid arthritis (RA) patients on hemodialysis (HD). A maintenance dose of 25 mg or less was administered either once per day or once following HD. The Lansbury activity index improved in all patients. The blood concentrations of MZR before and after HD were 0.33-1.79 μg/ml and 0-0.93 μg/ml, respectively. Hence, the rate of elimination by HD ranged from 50.3% to 83.4%. As far as side effects were concerned, alopecia was seen in two patients, and one patient developed shingles. However, the severity of these symptoms was mild and, after discontinuing or reducing the dose of MZR for a certain period of time, we were able to continue its administration. These findings suggest that the long-term administration of MZR is a useful treatment for RA patients on HD.