OBJECTIVE: To compare the bioavailability of three generic brands of carbamazepine tablets with that of a proprietary brand in adult patients with epilepsy. DESIGN: A double-blind, randomized, three-phase crossover study. SETTING: A psychiatric facility. PARTICIPANTS: Eighteen patients with epilepsy who had taken carbamazepine at least 5 months before entering the study. MAIN OUTCOME MEASURES: Ten blood specimens from each patient were collected at steady-state. Plasma concentration of carbamazepine was analyzed for pharmacokinetic parameters such as maximum plasma concentration (Cmax), mean time to reach maximum concentration (tmax), and mean AUC. RESULTS: There were no statistically significant differences in these parameters among four brands of carbamazepine. However, when comparing the 90% CI of AUC of three generic brands with that of the proprietary brand, the AUC of two generic brands lay within a range of 80% to 120%. The effects of gender and each brand of carbamazepine on these pharmacokinetic parameters were also analyzed. Breakthrough seizures occurred even though the plasma concentration of carbamazepine was therapeutic. CONCLUSIONS: The bioavailability of two generic brands of carbamazepine tablets (Carmapine and Carzepine) and the proprietary brand (Tegretol) were equivalent in this sample of adult patients with epilepsy.
RCT Entities:
OBJECTIVE: To compare the bioavailability of three generic brands of carbamazepine tablets with that of a proprietary brand in adult patients with epilepsy. DESIGN: A double-blind, randomized, three-phase crossover study. SETTING: A psychiatric facility. PARTICIPANTS: Eighteen patients with epilepsy who had taken carbamazepine at least 5 months before entering the study. MAIN OUTCOME MEASURES: Ten blood specimens from each patient were collected at steady-state. Plasma concentration of carbamazepine was analyzed for pharmacokinetic parameters such as maximum plasma concentration (Cmax), mean time to reach maximum concentration (tmax), and mean AUC. RESULTS: There were no statistically significant differences in these parameters among four brands of carbamazepine. However, when comparing the 90% CI of AUC of three generic brands with that of the proprietary brand, the AUC of two generic brands lay within a range of 80% to 120%. The effects of gender and each brand of carbamazepine on these pharmacokinetic parameters were also analyzed. Breakthrough seizures occurred even though the plasma concentration of carbamazepine was therapeutic. CONCLUSIONS: The bioavailability of two generic brands of carbamazepine tablets (Carmapine and Carzepine) and the proprietary brand (Tegretol) were equivalent in this sample of adult patients with epilepsy.
Authors: Aaron S Kesselheim; Margaret R Stedman; Ellen J Bubrick; Joshua J Gagne; Alexander S Misono; Joy L Lee; M Alan Brookhart; Jerry Avorn; William H Shrank Journal: Drugs Date: 2010-03-26 Impact factor: 9.546
Authors: Bernhard J Steinhoff; Uwe Runge; Otto W Witte; Hermann Stefan; Andreas Hufnagel; Thomas Mayer; Günter Krämer Journal: Ther Clin Risk Manag Date: 2009-06-22 Impact factor: 2.423