An Attempt to Analyze with the Compartment Model on Disposition of Furosemide in the Rat

Abstract

When the plasma concentration-time curves of furosemide after bolus intravenous injection in the rat were analyzed, it seemed that three-exponential equation fitted in the lower dose, and two-exponential equation in the higher dose. However, the relationship between doses and areas under the plasma concentration-time curve (AUC) was nonlinear over the dose range from 10 mg/kg to 30 mg/kg. From the one-compartment model analysis with constant-rate intravenous infusion of drug, parameters for Michaelis-Menten elimination kinetics in hepato-portal compartment were estimated by using the graphical technique. The pharmacokinetics of furosemide could be expressed by the proposed nonlinear model with two saturable processes at the elimination in hopato-portal compartment and the urinary excretion.