WITHDRAWN: Oxcarbazepine add-on for drug-resistant partial epilepsy

Most people with epilepsy have a good prognosis and their seizures can be well controlled with the use of a single antiepileptic drug, but up to 30% develop refractory epilepsy, especially those with partial seizures. In this review we summarize the current evidence regarding oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy.

To evaluate the effects of oxcarbazepine when used as an add-on treatment for drug-resistant partial epilepsy.

We searched the Cochrane Epilepsy Group's Specialized Register (28 March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2006), MEDLINE (1966 to March 2006). No language restrictions were imposed. We checked the reference lists of retrieved studies for additional reports of relevant studies. We also contacted Novartis (manufacturers of oxcarbazepine) and experts in the field.

Randomized, placebo-controlled, double-blinded, add-on trials of oxcarbazepine in patients with drug-resistant partial epilepsy.

Two review authors independently assessed trials for inclusion and extracted the relevant data. The following outcomes were assessed : (a) 50% or greater reduction in seizure frequency; (b) treatment withdrawal (any reason); (c) side effects. Primary analyses were intention-to-treat. Summary odds ratios were estimated for each outcome.

Two trials were included representing 961 randomized patients.Overall Odds Ratio (OR) (95% Confidence Interval (CIs)) for 50% or greater reduction in seizure frequency compared to placebo 2.96 (2.20, 4.00).Treatment withdrawal OR (95% CIs) compared to placebo 2.17 (1.59, 2.97).Side effects: OR (99% CIs) compared to placebo, ataxia 2.93 (1.72, 4.99); dizziness 3.05 (1.99, 4.67); fatigue 1.80 (1.02, 3.19); nausea 2.88 (1.77, 4.69); somnolence 2.55 (1.84, 3.55); diplopia 4.32 (2.65, 7.04), were significantly associated with oxcarbazepine.

Oxcarbazepine has efficacy as an add-on treatment in patients with drug-resistant partial epilepsy, both in adults and children. However, trials reviewed were of relatively short duration, and provide no evidence about the long-term effects of oxcarbazepine. Results cannot be extrapolated to monotherapy or to patients with other epilepsy types.