Comparative Pharmacokinetics/Pharmacodynamics of Clopidogrel Besylate and Clopidogrel Bisulfate in Healthy Korean Subjects

Abstract

Clopidogrel selectively inhibits platelet aggregation. Clopidogrel bisulfate (Plavix(®)) was first developed for atherothrombosis prevention and is commonly prescribed for this indication. A new clopidogrel formulation, clopidogrel besylate (KOVIX(®)), has recently been developed. This study was designed to compare the multiple-dose pharmacokinetics/pharmacodynamics and tolerability of clopidogrel besylate with those of clopidogrel bisulfate in 40healthy male subjects. This was an open-label, randomized-sequence, multiple-dose, two-period, two-treatment crossover study. The subjects were randomly assigned to a sequence group that received two treatments: clopidogrel besylate 75mg followed by clopidogrel bisulfate 75mg, or vice versa. The subjects received a 300-mg loading dose on day 1 followed by 75mg daily for the next 4days. Serial blood samples were collected to determine the concentrations of clopidogrel and its carboxylic acid metabolite, SR26334. Platelet aggregation and bleeding times were measured. Tolerability was evaluated throughout the study. The clopidogrel plasma concentration-time profiles of the formulations were similar. The measured pharmacokinetic parameters did not differ significantly between the clopidogrel besylate and clopidogrel bisulfate groups. The geometric mean ratios of the clopidogrel besylate group to the clopidogrel bisulfate group with respect to the maximum plasma concentration (C(max)) and the area under the concentration-time curve (AUC) from time zero to the time of last measurable concentration (AUC(last)) were 0.96 (90% confidence interval [CI] 0.82, 1.12) and 0.95 (0.81, 1.11), respectively. Moreover, the pharmacokinetic parameters of SR26334 did not differ significantly between the two treatment groups. Furthermore, the areas under the platelet aggregation inhibition-time curves (AUIC) and the maximum inhibitory effects (I(max)) did not differ significantly between the two groups. The geometric mean ratios (clopidogrel besylate to clopidogrel bisulfate) were 1.01 (90% CI 0.95, 1.08) for the I(max) and 0.98 (0.89, 1.07) for the AUIC. Both formulations were well tolerated and exhibited comparable safety profiles. This study demonstrated that the pharmacokinetic/pharmacodynamic profiles of clopidogrel besylate were not significantly different from those of clopidogrel bisulfate. Both formulations were well tolerated in healthy subjects.