Pharmacokinetics and Pharmacodynamics of Intravenous Famotidine in Healthy Volunteers / 第二军医大学学报

ABSTRACT

The pharmacokinetics and pharmacodynamics of famotidine were investigated in 10 healthy male volunteers after single intravenous administration of 20 mg. The blood drug levels were determined by a high performance liquid chromatography. The 1gC of famotidine in plasma vs time curve were found to be twcncompartment open model in healthy volunteers. The terminal half-life averaged 3.16h; the total distribution volume 99.40L; the total plasma clearance 392.12ml/min; the area under the plasma concentration curve 1057.45 h?ng/ml. A mathematic equation describing the whole course of blood drug levels in relation to inhibitory effects on intragastric acid output is as follows E= 100?C2.60/(C2.60+14.712.60). The constant 14.71 is EC50 (ng/ml), the blood drug concentration producing 50% of maximal pharmacological effects. Prediction of pharmacodynamic effects from blood drug level and vice versa becomes possible by using the mathematic equation.