Effects of dialysis on the pharmacokinetics of salazosulfapyridine.

There was no standard or report for the treatment of rheumatoid arthritis (RA) patients on hemodialysis with Salazosulfapyridine (SASP). We examined the pharmacokinetics of SASP and its metabolites in RA patient on hemodialysis. Hemodialysis was started 2 h after administration of SASP at a dose of 250 or 500 mg. Blood samples were took 8 times during the observation period. The concentration of SASP and its metabolites (SP, Ac-SP) in blood sample were measured. There was no difference for the concentration of SASP before and after hemodialysis. Results showed SASP was nondialyzable, but SP and AC-SP were dialyzable. At a dose of 500 mg, AUC0-∞ of SASP and SP were higher than healthy volunteer. Therapy with SASP for hemodialysis RA should be started at a lower dose for adverse event risk.