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Elucidation of the rate-determining process in the overall hepatic elimination of drugs is critical for predicting their intrinsic hepatic clearance and the impact of variation of sequestration clearance on their systemic concentration. The present study investigated the rate-determining process in the overall hepatic elimination of the HMG-CoA reductase inhibitors pravastatin, pitavastatin, atorvastatin, and fluvastatin both in rats and humans. The uptake of these statins was saturable in both rat and human hepatocytes. Intrinsic hepatic clearance obtained by in vivo pharmacokinetic analysis in rats was close to the uptake clearance determined by the multiple indicator dilution method but much greater than the intrinsic metabolic clearance extrapolated from an in vitro model using liver microsomes. In vivo uptake clearance of the statins in humans (pravastatin, 1.44; pitavastatin, 30.6; atorvastatin, 12.7; and fluvastatin, 62.9 ml …