title: Association between antiepileptic drug switching and epilepsy-related events.
abstract: Switching between bioequivalent antiepileptic drugs (AEDs) in patients with epilepsy remains a concern because of possible untoward effects owing to a narrow therapeutic range. We investigated the association between switching A-rated AEDs and epilepsy-related events. We conducted a case-control study using claims from the MarketScan database. Cases were defined by an emergently treated epilepsy-related event with the primary diagnosis of epilepsy. Controls had an epilepsy outpatient office visit. Eighty-four of 757 (11.1%) cases and 147 of 2271 (6.5%) controls experienced an A-rated switch. The odds of an epilepsy-related event were 1.78-fold higher for switchers (95% CI 1.35 to 2.36) and, when adjusted for gender and total number of AED prescriptions filled, 1.57-fold higher (95% CI=1.17-2.10). Switching between A-rated formulations of AEDs is associated with an increased risk of emergently treated epilepsy-related events. These findings suggest that care should be taken when considering a switch between A-rated AEDs in patients with epilepsy.
authors.affiliation: Pharmaceutical Outcomes Research and Policy Program, University of Washington, 1959 NE Pacific Avenue, Seattle, WA 98195, USA.
authors.forename: Ryan N
authors.initials: RN
authors.lastname: Hansen
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Campbell
authors.forename: Sean D
authors.initials: SD
authors.lastname: Sullivan
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use*; D016022:Case-Control Studies; D002626:Chemistry, Pharmaceutical; D002648:Child; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D004827:Epilepsy / Q000145:classification / Q000188:drug therapy* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012640:Seizures / Q000145:classification; D012959:Socioeconomic Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000927:Anticonvulsants