Eslicarbazepine acetate add-on for drug-resistant partial epilepsy

This is an updated version of the Cochrane Review published in the Cochrane Library 2011, Issue 12.The majority of people with epilepsy have a good prognosis, but up to 30% of people continue to have seizures despite several regimens of antiepileptic drugs. In this review, we summarized the current evidence regarding eslicarbazepine acetate (ESL) when used as an add-on treatment for drug-resistant partial epilepsy.

To evaluate the efficacy and tolerability of ESL when used as an add-on treatment for people with drug-resistant partial epilepsy.

The searches for the original review were run in November 2011. Subsequently, we searched the Cochrane Epilepsy Group Specialized Register (6 December 2016), the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 11) and MEDLINE (1946 to 6 December 2016). There were no language restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of ESL and experts in the field for information about any unpublished or ongoing studies.

Randomized placebo controlled double-blind add-on trials of ESL in people with drug-resistant partial epilepsy.

Two review authors independently selected trials for inclusion and extracted data. Outcomes investigated included 50% or greater reduction in seizure frequency, seizure freedom, treatment withdrawal, adverse effects, and drug interactions. Primary analyses were by intention to treat (ITT). The dose-response relationship was evaluated in regression models.

We included five trials (1799 participants) rated at low risk of bias; all studies were funded by BIAL. The overall risk ratio (RR) with 95% confidence interval (CI) for 50% or greater reduction in seizure frequency was 1.71 (95% CI 1.42 to 2.05). Dose regression analysis showed evidence that ESL reduced seizure frequency with an increase in efficacy with increasing doses of ESL. ESL was significantly associated with seizure freedom (RR 2.90, 95% CI 1.49 to 5.68). Participants were more likely to have ESL withdrawn for adverse effects (RR 2.66, 95% CI 1.42 to 4.96) but not for any reason (RR 1.19, 95% CI 0.86 to 1.64). The following adverse effects were significantly associated with ESL: dizziness (RR 2.81, 99% CI 1.86 to 4.27); nausea (RR 2.61, 99% CI 1.36 to 5.01); diplopia (RR 4.14, 99% CI 1.74 to 9.84); somnolence (RR 1.71, 99% CI 1.11 to 2.63) and vomiting (RR 3.30, 99% CI 1.34 to 8.13). Overall the quality of the evidence was rated as moderate to high.

ESL reduces seizure frequency when used as an add-on treatment for people with drug-resistant partial epilepsy. The trials included in this review were of short-term duration and focused on adults. One new trial has been included in this update, but the conclusions are unchanged.