PT  - JOURNAL ARTICLE
AU  - Kesselheim, Aaron S.
AU  - Bykov, Katsiaryna
AU  - Gagne, Joshua J.
AU  - Wang, Shirley V.
AU  - Choudhry, Niteesh K.
TI  - Switching generic antiepileptic drug manufacturer not linked to seizures
AID  - 10.1212/WNL.0000000000003259
DP  - 2016 Oct 25
TA  - Neurology
PG  - 1796--1801
VI  - 87
IP  - 17
4099  - http://n.neurology.org/content/87/17/1796.short
4100  - http://n.neurology.org/content/87/17/1796.full
SO  - Neurology2016 Oct 25; 87
AB  - Objective: With more antiepileptic drugs (AED) becoming available in generic form, we estimated the risk of seizure-related events associated with refilling generic AEDs and the effect of switching between different manufacturers of the same generic drug.Methods: We designed a population-based case-crossover study using the Medicaid Analytic eXtract and a US commercial health insurance database. We identified 83,001 generic AED users who experienced a seizure-related hospital admission or emergency room visit between 2000 and 2013 and assessed whether they received a refill of the same AED from the same manufacturer or a different manufacturer. Patients served as their own controls and conditional logistic regression was used to compare exposure to a refill during the hazard period, defined as days 2–36 preceding the seizure-related event, to exposure during the control period, defined as days 51–85 preceding the seizure-related event.Results: Generic AED refilling was associated with an 8% increase in the odds of seizure-related events (odds ratio [OR] 1.08; 95% confidence interval [CI] 1.06–1.11). The OR following a switch to a different manufacturer of the same AED was 1.09 (95% CI 1.03–1.15); however, after adjusting for the process of refilling, there was no association between switching and seizure-related hospital visits (OR 1.00; 95% CI 0.94–1.07).Conclusions: Among patients on a generic AED, refilling the same AED was associated with an elevated risk of seizure-related event; however, there was no additional risk from switching during that refill to a different manufacturer. Generic AEDs available to US patients, with Food and Drug Administration–validated bioequivalence, appear to be safe clinical choices.AED=antiepileptic drug; CI=confidence interval; ER=emergency room; FDA=Food and Drug Administration; ICD-9-CM=International Classification of Diseases, 9th Revision, Clinical Modification; NDC=National Drug Code; OR=odds ratio