Abstract
To investigate a possible pharmacokinetic interaction between 4-quinolone and fenbufen, plasma concentration-time profiles and serum protein binding of norfloxacin, fenbufen and its active metabolite, felbinac, were examined in rats to which were given an intravenous dose of norfloxacin (5mg/kg), fenbufen (10mg/kg) alone or concomitantly. Although coadministered fenbufen increased the plasma elimination half-life of norfloxacin only slightly, it showed no effect on other pharmacokinetic parameters including total body clearance for norfloxacin. The extent of protein binding of norfloxacin tended to be slightly reduced by fenbufen or felbinac in vivo and in vitro. The pharmacokinetic parameters and serum protein binding of fenbufen and felbinac were not affected at all by coadministered norfloxacin. These results suggest that there may be only a minor possibility of the pharmacokinetic interaction between norfloxacin and fenbufen.
