Efficacy and safety of eslicarbazepine acetate monotherapy in patients converting from carbamazepine.

OBJECTIVE: To evaluate the influence of prior use of carbamazepine (CBZ) and other antiepileptic drugs (AEDs) with a putatively similar mechanism of action (inhibition of voltage-gated sodium channels; VGSCs) on seizure outcomes and tolerability when converting to eslicarbazepine acetate (ESL), using data pooled from 2 controlled conversion-to-ESL monotherapy trials (studies: 093-045, 093-046). METHODS: Adults with treatment-resistant focal (partial-onset) seizures were randomized 2:1 to ESL 1600 or 1200 mg once daily. The primary efficacy endpoint was study exit (meeting predefined exit criteria related to worsening seizure control) versus an historical control group. Other endpoints included change in seizure frequency, responder rate, and tolerability. Endpoints were analyzed for subgroups of patients who received CBZ (or any VGSC inhibitor [VGSCi]) during baseline versus those who received other AEDs. RESULTS: Of 365 patients in the studies, 332 were evaluable for efficacy. The higher risk of study exit in the subgroups that received CBZ (or any VGSCi) during baseline, versus other AEDs, was not statistically significant (hazard ratios were 1.49 for +CBZ vs -CBZ [P = .10] and 1.27 for +VGSCi vs. -VGSCi [P = .33]). Reductions in seizure frequency and responder rates were lower in patients who converted from CBZ or other VGSCi compared with those who converted from other AEDs. There were no notable differences in overall tolerability between subgroups, but the incidence of some adverse events (eg, dizziness, somnolence, nausea) differed between subgroups and/or between treatment periods. SIGNIFICANCE: Baseline use of CBZ or other major putative VGSC inhibitors did not appear to significantly increase the risk of study exit due to worsening seizure control, or to increase the frequency of side effects when converting to ESL monotherapy. However, bigger improvements in efficacy may be possible in patients converting to ESL monotherapy from an AED regimen that does not include a VGSC inhibitor.

Influence of titration schedule and maintenance dose on the tolerability of adjunctive eslicarbazepine acetate: An integrated analysis of three randomized placebo-controlled trials.

OBJECTIVE: To examine the influence of titration schedule and maintenance dose on the incidence and type of treatment-emergent adverse events (TEAEs) associated with adjunctive eslicarbazepine acetate (ESL). METHODS: Data from three randomized, double-blind, placebo-controlled trials were analyzed. Patients with refractory partial-onset seizures were randomized to maintenance doses of ESL 400, 800, or 1200mg QD (dosing was initiated at 400 or 800mg QD) or placebo. The incidence of TEAEs was analyzed during the double-blind period (2-week titration phase; 12-week maintenance phase), according to the randomized maintenance dose and the titration schedule. RESULTS: 1447 patients were included in the analysis. During the first week of treatment, 62% of patients taking ESL 800mg QD had ≥1 TEAE, vs 35% of those taking 400mg QD and 32% of the placebo group; dizziness, somnolence, nausea, and headache were numerically more frequent in patients taking ESL 800mg than those taking ESL 400mg QD. During the double-blind period, the incidences of common TEAEs were lower in patients who initiated ESL at 400mg vs 800mg QD. For the 800 and 1200mg QD maintenance doses, rates of TEAEs leading to discontinuation were lower in patients who began treatment with 400mg than in those who began taking ESL 800mg QD. CONCLUSIONS: Initiation of ESL at 800mg QD is feasible. However, initiating treatment with ESL 400mg QD for 1 or 2 weeks is recommended, being associated with a lower incidence of TEAEs, and related discontinuations. For some patients, treatment may be initiated at 800mg QD, if the need for more immediate seizure reduction outweighs concerns about increased risk of adverse reactions during initiation.