Pharmacokinetics of fusidic acid in laboratory animals

The ability of evaluate the efficacy of fusidic acid in animal models of infectious disease is limited by the absence of pharmacokinetic data for the agent in laboratory animals. In our study, aspects of fusidic acid pharmacokinetics were compared in rats (Rattus norwegicus), mice (Mus musculus), rabbits (Oryctolagus cuniculus), and guinea pigs (Cavia porcellus). Sodium fusidate was poorly absorbed after oral administration to rats, although limited absorption occurred in guinea pigs, mice, and rabbits. Subcutaneous injections of diethanolamine fusidate to laboratory rats, however, achieved a serum profile similar to that observed in humans. There was no evidence of drug accumulation in rats given repeated subcutaneous doses of diethanolamine fusidate during a 4-day period, but rabbits showed clear evidence of a cumulative effect.