Post-authorisation study of eslicarbazepine as treatment for drug-resistant epilepsy: preliminary results

Overnight switch from carbamazepine to eslicarbazepine in a real-life clinical scenario: a retrospective study

BACKGROUND

Carbamazepine (CBZ) is a first-choice anti-seizure medication (ASM) whose efficacy is often invalidated by adverse effects (AEs). Eslicarbazepine (ESL) is a structural derivative of CBZ with better pharmacokinetic/tolerability profiles. We describe our experience of the overnight CBZ to ESL switch in people with epilepsy (PwE) to improve seizure control, AEs, and ASMs adherence.

METHODS

We retrospectively included 19 PwE (12 females, 53 ± 21 years old) who underwent CBZ to ESL overnight switch due to single/multiple issues: poor efficacy (pEff, N = 8, 42%), tolerability (pToll, N = 11, 58%), adherence (pAdh, N = 2, 10%). 9/19 (47%) had psychiatric comorbidities. Clinical variables, seizure frequency, and AEs were recorded at switch time (T0) after 3.5 ± 3 (T1) and 6.5 ± 1.5 months (T2).

RESULTS

At T1, in pEff group, 1/8 (13%) was seizure free, 2/8 (25%) were responders (> 50% seizure reduction), 2/8 (25%) had no seizure changes, 3/8 (37%) had seizure worsening; the latter were those with the most severe epilepsy and encephalopathy. In pToll group, all PwE experienced AEs disappearance/amelioration. In pAdh group, all PwE reported adherence amelioration. Four dropouts. At T2, no changes were recorded within groups, while in the whole sample, 6/15 (40%) were responders, and 4/15 (27%) were seizure-free. No one complained of Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation psychiatric worsening, while 6/19 (32%) experienced mood/behavior benefits.

CONCLUSIONS

CBZ to ESL overnight switch offers an opportunity to improve efficacy, tolerability, adherence, and psychiatric symptoms.

The evidence for switching dibenzazepines in people with epilepsy

The dibenzazepines particularly carbamazepine are associated with known adverse effects (AEs) and drug to drug interactions. Eslicarbazepine acetate (ESL) is structurally distinct from other members of the dibenzazepine family and has the advantage of once daily dosing. Observational and trial data report successful switching from older dibenzazepines to ESL. The evidence base for doing so is unclear and not standardized. This is a literature review following the PRISMA scoping guidelines identifying the evidence of switching dibenzazepines. Transition methods, ratios, tolerance to change, adverse effects and retention post-change were evaluated. Study quality was assessed using the Oxford Centre for Evidence Based Medicine levels of evidence. Seven studies investigated the outcome of transition between carbamazepine and or oxcarbazepine to ESL, with specific data on the transition dose ratio and scheduling. The available data suggest that the overnight transition between oxcarbazepine and ESL in a 1:1 ratio (most common) is generally well tolerated with high retention rates. The transition showed improvement in adverse events associated with oxcarbazepine across a variety of domains. Almost 60% transitioned because of adverse events experienced no further symptoms at 12 months. There is less data on the transition from carbamazepine to ESL. The evidence available suggests an overnight transition in the ratio of 1:1.3-1.5. The retention rate following transition from carbamazepine to ESL was 69% (follow-up of 4 months) with almost half of those transitioned because of adverse events experiencing no further symptoms. There is Grade C evidence available to help guide clinicians in the transition.