No abstract

In this study, the effects of three non-steroidal anti-inflammatory drugs, alclofenac, diclofenac and tiaprofenic acid, on the plasma level of sulfamethizole were investigated in rats. The persistence of sulfamethizole in plasma was prolonged by coadministration of each anti-inflammatory drug. In experiments to investigate the renal excretion of sulfamethizole, the clearance ratio of sulfamethizole was markedly decreased after infusion of each anti-inflammatory drug. From these results, it is speculated that prolongation of the persistence of sulfamethizole in plasma by alclofenac, diclofenac or tiaprofenic acid is mainly caused by competitive interactions between sulfamethizole and alclofenac, diclofenac or tiaprofenic acid at the renal secretory level.

The effects of three non-steroidal anti-inflammatory drugs, ibufenac, sulindac and mepirizole, on the renal excretion of sulfamethizole in rats were investigated, in order to clarify the mechanisms involved. The clearance ratio of sulfamethizole was markedly decreased after infusion of ibufenac, while sulindac or mepirizole had no effect on the clearance ratio of sulfamethizole. From this result, it is speculated that the decrease of renal excretion of sulfamethizole caused by ibufenac is mainly due to competitive interaction between sulfamethizole and ibufenac at the renal secretory level. The correlation between the chemical structures of some anionic non-steroidal anti-inflammatory drugs and the characteristics of renal tubular transport is discussed.