Oxcarbazepine: new preparation. An alternative to carbamazepine in partial epilepsy.

(1) The reference treatment for partial epilepsy in adults and children is carbamazepine. (2) Oxcarbazepine is available in the European Union for the treatment of partial epilepsy in adults and children aged over 6 years, alone or in combination with other antiepileptic drugs. (3) The clinical file on oxcarbazepine monotherapy of recent-onset generalised or partial epilepsy mainly contains data from one trial versus carbamazepine, two trials versus phenytoin, and one trial versus valproate sodium. In these trials, 52-60% of patients had no seizures on oxcarbazepine, a proportion not significantly different from that obtained with the comparators. Oxcarbazepine may, in fact, be slightly less effective than carbamazepine. (4) For refractory partial epilepsy (especially forms refractory to carbamazepine), oxcarbazepine is more effective than a placebo, when combined with the inadequately effective treatment, as shown in two trials. Two dose-finding studies show that 2 400 mg/day oxcarbazepine is more effective than 300 mg/day. (5) In trials comparing single-drug treatments there were fewer withdrawals for adverse events among patients on oxcarbazepine than among those on carbamazepine or phenytoin. Compared with carbamazepine, the risk of cutaneous hypersensitivity reactions seems to be lower with oxcarbazepine, while the risk of hyponatraemia is higher. This risk of hyponatraemia necessitates laboratory monitoring. (6) The risk of clinically significant interactions appears to be lower on oxcarbazepine than on carbamazepine, and is limited mainly to combined contraceptives (contraceptive inefficacy) and phenytoin. (7) In practice, carbamazepine remains the reference treatment for partial epilepsy, but oxcarbazepine is one of several second-line options, either alone or in combination with other antiepileptics.