Population pharmacokinetics of lidocaine in Korean adults during general anesthesia

Population pharmacokinetics of lidocaine (L) was determined in Korean adults during general anesthesia with enflurane, nitrous oxide, and oxygen (50%). After induction of anesthesia, tracheal intubation, and insertion of venous and arterial catheters, L was administered by intravenous bolus at 1, 2 or 3 mg/kg. Various times after dosing with L, 182 blood samples were obtained from contralateral radial artery of 23 individuals. L concentrations in plasma were determined by immunofluorescence assay. Concentration-time data were analyzed using a 2-compartment open model by NONMEM, allowing for interindividual differences. Fit of the model from all individuals gave following estimated values; distribution half-life (t_1/2α) of 0.49 min (interindividual variability; 16% in CV), elimination half-life (t_1/2β) of 18.68 min (20%), clearance of 13.4 mL/min/kg (20%), central volume of distribution (V_C) of 27.9 mL/kg (22%), and steady-state volume of distribution (V_SS) of 279.1 mL/kg (39%). These parameters showed considerable differences from those reported earlier for other population.