The impact of background antiepileptic drugs on the efficacy and safety of pregabalin in treating partial-onset seizures: A post hoc analysis of combined clinical trials

Abstract

Pregabalin is used as adjunctive treatment for partial-onset seizures and is often combined with multiple antiepileptic drugs (AEDs) from different classes. The objectives of this post hoc analysis were to evaluate the efficacy and safety of pregabalin when added to different AED regimens and to identify specific AED combinations that in conjunction with pregabalin yield high responder rates. Data from six double-blind, randomized studies of pregabalin in patients with partial-onset seizures were pooled for analysis (N=1775). When the treatment groups (placebo, 150mg, 300mg, 600mg, and flexible dose) were stratified by the number of concomitant AEDs (one, two or three or more), modeling results suggested that the magnitude of improvement on either ≥50% responder rate or mean response ratio remained consistent regardless of the number of concomitant AEDs. Adverse events were typical of pregabalin and, in general, did not vary as the number of concomitant AEDs increased. A cluster analysis was performed to identify possible combinations of AEDs that yielded high ≥50% responder rates. The majority of patients (>90%) fell within two clusters that yielded high responder rates, while <10% of the patients fell within two clusters that yielded low responder rates. Numerous AED combinations, ranging from 6 to 11, occurred within each cluster. In summary, pregabalin provided a consistent improvement in seizure reduction and comparable tolerability in patients with partial-onset epilepsy regardless of the number of concomitant AEDs.