Gemfibrozil absorption and elimination in kidney and liver disease

Summary The disposition of the lipid-lowering drug gemfibrozil was studied in patients with either renal (n= 8) or hepatic disease (n= 8) and compared to those of healthy volunteers (n= 6). Gemfibrozil was determined in plasma and urine by means of a HPLC method. Urine was also analyzed for gemfibrozil conjugates.Following oral administration of 900 mg gemfibrozil, maximal plasma levels of the parent drug were 46.1±15.8 g/ml, attained after 2.2±1.1 h. In chronic renal failure and in liver cirrhosis the plasma concentrations of gemfibrozil did not significantly differ from that of controls except in those patients who were comedicated with antacids. These patients had significantly lower C_max and AUC values. The elimination half-life of the drug was 1.5 h in controls, 2.4 h in renal failure, and 2.1 h in liver disease. In healthy volunteers, only 0.02 to 0.15% of the given dose was recovered in the urine as parent gemfibrozil, while conjugates made up 7–14%. In patients with renal failure also, only traces of parent gemfibrozil could be detected, and conjugates accounted for 0.5–9.8%. In those with liver disease, however, about 0.1–0.2% were recovered in urine as parent gemfibrozil and up to 50% as conjugates. Strikingly, the amount of excreted conjugates in the urine was positively correlated to the direct bilirubin plasma concentration. It can be concluded that the elimination of gemfibrozil is not significantly influenced by renal failure. However, comedication with antacids markedly reduced plasma disposition of the drug. Patients with severe liver disease excreted more conjugated gemfibrozil via the kidney than did healthy controls. Thus, transfer across the canalicular cell membrane to the bile duct, rather than drug metabolization, is primarily disturbed in liver disease. Gemfibrozil accumulation is unlikely to occur in either kidney or liver disease.Abbreviations Cl_r creatinine clearance (ml/min) - HPLC high pressure liquid chromatography - C_max maximal plasma concentration (g/ml) - t_max time (h) after which C_max is attained - k_e elimination rate constant (h^–1) - t_1/2 elimination half-life (h) - A_e amount of drug excreted into the urine (% of given dose) - MRT mean residence time (h) - AUMC area under the first moment curve (g h²/ml) - AUC area under the plasma level time curve (g·h/ml) - ANOVA analysis of variance The paper is gratefully dedicated to G.W. Löhr