A Cochrane review included 2 studies with individual patient data of a total of 480 subjects. One trial recruited adults only another one children and adolescents only. Both trials recruited participants with partial onset and with generalised tonic-clonic seizures without partial onset. For remission outcomes, a HR > 1 indicates an advantage to phenytoin and for first seizure and withdrawal outcomes a HR > 1 indicates an advantage to oxcarbazepine. Oxcarbazepine was significantly better than phenytoin for time to treatment withdrawal (HR 1.65, 95% CI 1.08 to 2.52; 2 trials, n=480), but there was no overall difference between oxcarbazepine and phenytoin for time to 6-month remission: HR 0.90, 95% CI 0.70 to 1.15; time to 12-month remission: HR 0.92, 95% CI 0.68 to 1.24; time to first seizure: HR 1.07, 95% CI 0.83 to 1.39). Results indicate a statistically significant advantage for oxcarbazepine over phenytoin for time to treatment withdrawal, but insufficient evidence to suggest a difference between the drugs for other outcomes. Results stratified by seizure type indicated no significant advantage for either drug for patients with generalized onset seizures, but a significant advantage in time to withdrawal for oxcarbazepine for patients with partial onset seizures (HR 1.95; 95% CI 1.15 to 3.33; 2 trials, n=333).
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in patients: children and adults) and imprecise results (few patients and wide confidence intervals).