Eslicarbazepine acetate add-on for drug-resistant partial epilepsy

The majority of people with epilepsy will have a good prognosis, but up to 30% of patients will 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.

We searched the Cochrane Epilepsy Group Specialized Register (3 November 2011), The Cochrane Central Register of Controlled Trials (CENTRAL issue 4 of 4, The Cochrane Library 2011), and MEDLINE (1948 to October week 4, 2011). 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 We also contacted the manufacturers of ESL and experts in the field for information about any unpublished or ongoing studies.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. The dose response relationship was evaluated in regression models.

Four trials (1146 participants) were included; all studies were funded by BIAL. The overall relative risk (RR) with 95% confidence interval (CIs) for 50% or greater reduction in seizure frequency outcome was 1.86 (95% CI 1.46 to 2.36). 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 3.04, 95% CI 1.44 to 6.42). Participants seemed more likely (albeit not significantly) to have ESL withdrawn for adverse effects (RR 2.26, 95% CI 0.98 to 5.21) but not for any reason (RR 1.07, 95% CI 0.73 to 1.57). The following adverse effects were significantly associated with ESL: dizziness (RR 3.09, 99% CI 1.76 to 5.43); nausea (RR 3.06, 99% CI 1.07 to 8.74); and diplopia (RR 3.73, 99% CI 1.19 to 11.64).

Eslicarbazepine acetate 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.