Rates of Adherence to Antiepileptic Drug Monotherapy for Focal Seizure

Electroencephalogram (EEG) chart of generalized epilepsy in a 6 year old child. The lines are consisitent with a typicalabsence seizure. The EEG is printed over a 3D MRI image of the brain in frontal view. (c) Sovereign
Investigators analyzed adherence to monotherapy antiepileptic drug therapy for patients with focal seizures receiving eslicarbazepine acetate vs generic carbamazepine and oxcarbazepine.

The following article is part of conference coverage from the 2019 American Academy of Neurology Annual Meeting (AAN 2019) in Philadelphia, PA. Neurology Advisor’s staff will be reporting breaking news associated with research conducted by leading experts in neurology. Check back for the latest news from AAN 2019.

PHILADELPHIA — Patients receiving eslicarbazepine acetate (ESL) monotherapy may have similar-to-higher rates of adherence compared with patients receiving generic carbamazepine (CBZ) and oxcarbazepine (OXC), according to research presented at the 2019 American Academy of Neurology’s Annual Meeting, held May 4-10, in Philadelphia.

This retrospective cohort study examined rates of adherence to antiepileptic drug (AED) monotherapy treatment for patients with focal seizures by comparing ESL with generic CBZ and OXC. Investigators analyzed patient-level administrative claims data from the Quintiles IMS PharMetrics Database. These drugs have varied side effect profiles, and prior research has suggested that the differences in adverse effects across AEDs are likely associated with treatment adherence differences. Prior research suggests nonadherence to AEDs is associated with adverse outcomes.

Adults with focal seizures, ≥12 months of enrollment, and claims for CBZ, ESL, or OXC monotherapy from April 2014 to March 2016 were included in the analysis. Baseline clinical and demographic characteristics of the 3 drug cohorts were examined, and OXC and CBZ participants were matched 1:1 to ESL participants using propensity scores according to those factors. AED adherence was measured using proportion days covered, and univariate testing across matched cohorts was used to compare the proportion of patients experiencing high adherence (proportion days covered ≥0.8).

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Initially, 441 participants received ESL, 171 received CBZ, and 676 received OXC, but after matching, only 163 CBZ participants and 379 OXC participants matched to ESL comparators remained. The proportion of ESL participants showing high adherence was significantly higher compared with the CBZ cohort (41.1% vs 30.1%; P =.037). Although the difference in the proportion of ESL and OXC participants with high adherence was numerically higher, it was nonsignificant (39.1% vs 34.8%; P =.23).

Study investigators conclude that “patients on ESL monotherapy may be associated with similar to higher adherence rates versus patients on generic CBZ or OXC.”

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Mehta D, Lee JH, Simeone J, Nordstrom B. Adherence to AED treatment for patients with focal seizure receiving monotherapy with eslicarbazepine acetate or prior generation generics: Evidence from a large US commercial claims database. Poster presented at: 2019 American Academy of Neurology Annual Meeting; May 9, 2019; Philadelphia, PA.