Antipyrine kinetics following partial blood exchange with Fluosol‐DA in the rat

The effects of partial blood exchange with Fluosol‐DA on hepatic microsomal oxidative metabolism have been studied in the rat. Antipyrine clearance (Cl) was used as an in‐vivo measure of the activity of the mixed function oxidase system. Rats were partially exchanged with Fluosol‐DA and dosed with antipyrine at selected time intervals following exchange. No change in antipyrine Cl was observed at 0.5 h, but there was a statistically significant decrease at 24 h and then an increase by more than 50% relative to control at 48 and 72 h. These data indicate that the effects of Fluosol‐DA on hepatic function are time‐dependent and that Fluosol‐DA has the potential both to inhibit and to enhance hepatic metabolism. The possibility of altered hepatic metabolism should be considered when patients transfused with Fluosol‐DA are given drugs primarily metabolized by the mixed function oxidase system. 1986 Royal Pharmaceutical Society of Great Britain