Patients with epilepsy and partial-onset seizures stayed on treatment longer and had fewer hospitalizations and emergency department visits when they took concomitant antiepileptic drugs with dissimilar mechanisms of action, according to an analysis published online June 9 in JAMA Neurology.
The study, the first of its kind in patients with partial-onset seizures, suggests that prescribing antiepileptics with different mechanisms of action (MOA) might optimize treatment outcomes when patients need more than one drug for seizure control, said Jay M. Margolis, Pharm.D., of Truven Health Analytics, Bethesda, Md., and his associates.
The investigators analyzed prescription claims data from 8,615 adults with epilepsy and partial-onset seizures who used two oral antiepileptics concomitantly for at least 90 days between 2005 and 2010 (JAMA Neurol. 2014 June 9 [doi:10.1001/jamaneurol.2014.808]). Data were from the Truven Health MarketScan Commercial Claims Database. The researchers divided the prescriptions into four categories: sodium channel blockers, gamma-aminobutyric acid analogs, synaptic vesicle protein 2A binders, and drugs with multiple MOAs.
Persistence on treatment served as a proxy for tolerability and seizure control, according to the investigators. They added that patients taking two drugs with different MOAs stayed on treatment up to 97 days longer, on average, and were significantly less likely to stop treatment than were patients prescribed two antiepileptics in the same category.
Furthermore, patients who took an oral gamma-aminobutyric acid analog and another antiepileptic with a different MOA were at lower risk of inpatient admission (odds ratio, 0.716; 95% confidence interval, 0.54-0.95; P = .02), compared with patients who took two gamma-aminobutyric acid analogs, said the investigators. Likewise, patients who took a sodium channel blocker plus another antiepileptic with a different MOA were at significantly lower risk of visiting an emergency department (OR, 0.85; 95% CI, 0.74-0.98; P = .03), compared with patients prescribed two sodium channel blockers. But the findings did not extend to all drug comparisons, possibly because the drug classes were not specific enough to detect differences between combinations, Dr. Margolis and his associates added. Future studies should explore factors that influence outcomes when patients take antiepileptics with different MOAs, they said,
Eisai Inc. funded the study. Truven Health Analytics employs two of the study’s coauthors and received research-related payments from Eisai Inc. The authors reported no other conflicts of interest.