Purpose: Evaluation of the efficacy of add-on valproate (VPA) or primidone (PRM) in patients with partial epilepsy unresponsive to carbamazepine (CBZ).
Methods: The 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.
Results: Significantly 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.
Conclusion: Our results indicated that the efficacy of the CBZ/VPA combination tends to be greater than the efficacy of the CBZ/PRM combination.