Intersex and interspecies pharmacokinetics of metoprolol after oral and intravenous dose administration in rats and mice

Aim: Intersex and interspecies metoprolol pharmacokinetics following intravenous and oral dose administration in rodents. Materials & methods: Oral and intravenous dose studies were conducted in rats and mice. Significant intersex differences were observed in peak plasma levels of metoprolol after oral dose in both the species. The plasma concentration (Cmax) was approximately sevenfold higher (270.356 ng/ml) in female compared with male rats (40.981 ng/ml) following oral dose administration. The Cmax observed for male (878.822 ± 75.5 ng/ml) was approximately twofold higher than in female mouse (404.016 ± 113.5 ng/ml) after oral dose administration. Conclusion: Sex and species related physioanatomical characteristics alters metoprolol pharmacokinetics. Such differences should be addressed in studies related to metoprolol interactions with concurrently administered drug candidates.