Have antiepileptic drug prescription claims changed following the FDA suicidality warning? An evaluation in a state Medicaid program.

OBJECTIVE

In January 2008, the Food and Drug Administration (FDA) communicated concerns and, in May 2009, issued a warning about an increased risk of suicidality for all antiepileptic drugs (AEDs). This research evaluated the association between the FDA suicidality communications and the AED prescription claims among members with epilepsy and/or psychiatric disorder.

METHODS

A longitudinal interrupted time-series design was utilized to evaluate Oklahoma Medicaid claims data from January 2006 through December 2009. The study included 9289 continuously eligible members with prevalent diagnoses of epilepsy and/or psychiatric disorder and at least one AED prescription claim. Trends, expressed as monthly changes in the log odds of AED prescription claims, were compared across three time periods: before (January 2006 to January 2008), during (February 2008 to May 2009), and after (June 2009 to December 2009) the FDA warning.

RESULTS

Before the FDA warning period, a significant upward trend of AED prescription claims of 0.01% per month (99% CI: 0.008% to 0.013%, p<0.0001) was estimated. In comparison to the prewarning period, no significant change in trend was detected during (-20.0%, 99% CI: -70.0% to 30.0%, p=0.34) or after (80.0%, 99% CI: -20.0% to 200.0%, p=0.03) the FDA warning period. After stratification, no diagnostic group (i.e., epilepsy alone, epilepsy and comorbid psychiatric disorder, and psychiatric disorder alone) experienced a significant change in trend during the entire study period (p>0.01).

CONCLUSIONS

During the time period considered, the FDA AED-related suicidality warning does not appear to have significantly affected prescription claims of AED medications for the study population.