Comparison of add-on valproate and primidone in carbamazepine-unresponsive patients with partial epilepsy

PurposeEvaluation of the efficacy of add-on valproate (VPA) or primidone (PRM) in patients with partial epilepsy unresponsive to carbamazepine (CBZ).MethodsThe trial was prospective and open. Patients, aged 8–58 years, with partial epilepsy who did not become seizure free on CBZ were randomized to either VPA add-on or PRM add-on. The baseline period and the evaluation period were both 3 months. Proportions of patients with different degrees of reduction in seizure frequency were determined.ResultsSignificantly more patients on VPA (51% of 68 patients) achieved a greater than 50% seizure reduction than on PRM (34% of 68 patients). There was no significant difference in percentage seizure free (26% and 16%, respectively) or in percentage treatment withdrawals due to adverse effects.ConclusionOur results indicated that the efficacy of the CBZ/VPA combination tends to be greater than the efficacy of the CBZ/PRM combination.