A comparative pharmacokinetic study of conventional and chewable carbamazepine in epileptic patients

Using an open substitution study design, conventional carbamazepine (Tegretol, CBZ-C and a chewable carbamazepine formulation (Tegretol Chewtabs, CBZ-CHEW) were compared in 12 patients with severe intractable epilepsy. During a dosing interval, no significant differences were observed with respect to trough or peak serum concentrations of CBZ and CBZ-10,11-epoxide (CBZ-E), the active metabolite. The area under the serum CBZ concentration-time curve for a dosing interval was (mean +/- s.e. mean) 146 +/- 10 mumols l-1 h on CBZ-C and 143 +/- 9 mumols l-1 h on CBZ-CHEW. The two formulations, therefore, have a similar pharmacokinetic profile and could be used interchangeably in the management of patients with epilepsy.