Antiepileptic use for epilepsy and nonepilepsy disorders: A population-based study (1998-2013).

Objective: To examine the trends in antiepileptic drug (AED) use among individuals living in Manitoba with and without a history of epilepsy.

Methods: Using data obtained from administrative health databases in Manitoba, we assessed the quarterly prevalence of AED use between 1998 and 2013 among individuals with and without a history of epilepsy using cross-sectional time series analysis.

Results: Over the study period, the number of individuals prescribed AEDs increased more than 3-fold, from 8,883 to 27,246. The prevalence of AED use among patients with epilepsy increased by 3%, from 789.6 per 1,000 in 1998/1999 to 813.9 per 1,000 in 2012/2013 (p < 0.001 after 2006). In contrast, we observed a 210% increase in AED use among patients without epilepsy from 6.8 to 21.1 per 1,000 over the same period (p < 0.001). We observed a 55-fold rise in gabapentin use among patients without a seizure disorder (from 0.2 to 11.1 per 1,000; p < 0.001), while gabapentin use among those with epilepsy increased only 2-fold, from 21.6 to 41.3 per 1,000 (p < 0.001).

Conclusions: There has been a marked increase in the prevalence of AED users over the last 15 years, with a large shift towards the use of newer antiepileptic agents (primarily gabapentin) among those without epilepsy. Further research on the effect of these trends on health and economic outcomes will be of interest for clinicians and policymakers.