To describe and evaluate the evidence from major randomized controlled clinical trials investigating the efficacy and tolerability of pregabalin as add-on therapy for patients with refractory partial epilepsy.

Medline/PubMed, Cochrane, Ovid, Md Consult, Google, and Herdin databases were searched to identify all randomized controlled clinical trials on the use of pregabalin as add-on therapy for refractory epilepsy. The data from the relevant trials was extracted on the basis of an intention-to-treat principle. Treatment effects were measured as odds ratios between pregabalin and placebo. Tests for heterogeneity was done using the Mantel-Haenszel method. Pooled estimates ( using a 95% confidence interval) were computed according to the random effects model. Efficacy measures or study endpoints used were responder rates, degree of seizure freedom, and frequency of treatment-related adverse events.

Four eligible randomized controlled trials, involving a total of 1 379 patients, were included in the study. The combmed odds ratio for the responder rate was 7.28 (95% CI 4.42-11 .98) in favor of add-on pregabalin therapy versus placebo, the treatment effect of which was noted to be statistically significant (p < 0.00001). Higher responder rates were noted with higher pregabalin doses. The most common adverse events during the treatment period were dizziness, somnolence, ataxia, and weight gain. The majority of adverse events was mild to moderate in intensity and is generally well tolerated. The combined odds ratio for seizure freedom was 1 .72 (95% CI 0.84-3.53) in favor of pregabalin, the treatment effect of which is, however, not statistically significant (p = 0. 1 4).

Pregabalin is an effective and fairly tolerable adjunctive therapy for the treatment of for patients with refractory focal seizures.