Immediate-release versus controlled-release carbamazepine in the treatment of epilepsy

Powell, Graham, Saunders, Matthew, Marson, Anthony G

Epilepsy is defined as the tendency to spontaneous, excessive neuronal discharge manifesting as seizures. It is a common disorder with an incidence of 50 per 100,000 per year and a prevalence of 0.5% to 1% (Hauser 1993) in the developed world.Carbamazepine (CBZ) is a widely used antiepileptic drug that is associated with a number of troublesome adverse events including dizziness, double vision and unsteadiness. These often occur during peaks in plasma concentration. The occurrence of such adverse events may limit the daily dose that can be tolerated and reduce the chances of seizure control for patients requiring higher doses (Vojvodic 2002). A controlled-release formulation of carbamazepine delivers the same dose over a longer period of time when compared to a standard formulation, thereby reducing post-dose peaks and potentially reducing adverse events associated with peak plasma levels.