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

Medline/PubMed, Cochrane, Ovid, MdConsult, Google, Herdin, and ClinicalTrials.gov databases were searched to identify all randomized controlled clinical trials on the use of pregabalin as add on therapy for refractory seizures. Data were extracted on the basis of an intention-to-treat principle. Treatment effects were measured as odds ratios between pregabalin and placebo. Data were analyzed using the Review Manager 4.2 software. Pooled estimates (using a 95% confidence interval) were computed using the random effects model. Study endpoints used were responder rates, seizure freedom, rates of adverse events, and discontinuation rates due to lack of efficacy and adverse events.

Four eligible randomized controlled trials comprising 1397 patients were included. Statistically significant responder rates (pooled OR 5.16; 95% Cl 3.27-8.13, p < 0.00001) in favor of pregabalin were demonstrated, with greater responder rates noted with increasing pregabalin doses. A trend towards seizure freedom in favor of pregabalin was also noted but statistically insignificant (pooled OR 1.21; 95% Cl 0.74-1.98, p = 0.45). Add-on pregabalin resulted in the occurrence of treatment-related adverse events (pooled OR 25.18; 95% Cl 8.88-71.44, p < 0.0001) but did not result in a statistically significant discontinuation (pooled OR 1.86; 95% Cl 0.98-3.54, p = 0.06). Adverse events were mild to moderate in severity and were generally well tolerated.

Add-on pregabalin is an effective and fairly tolerable adjunctive therapy for the treatment of patients with refractory partial seizures.