Study Examines Risk of Suicide-Related Behavior among Older Veterans Receiving Antiepileptic Drugs
BACKGROUND:
Since the 2008 FDA warning linking antiepileptic drugs (AEDs) to suicide-related behavior (SRB), study findings that examined SRB among AED users have been inconsistent. This retrospective cohort study examined the temporal relationship between new AED monotherapy exposure and SRB in older Veterans. Using VA data, investigators identified Veterans aged 65 years or older who received a new AED prescription between FY2004 and FY2006 (n=90,230). Suicide-related behavior was defined as suicidal ideation, suicide attempt, or self-inflicted injury that was documented in VA inpatient or outpatient files one year prior to and one year after the AED exposure date. Investigators also examined patient demographics and clinical covariates, such as psychiatric diagnosis (e.g., depression, PTSD, substance abuse) or other conditions previously associated with AED use or SRB, including epilepsy, chronic pain conditions (e.g., migraine, back pain), and dementia.
FINDINGS:
- Veterans receiving their first AED during the study period were more likely to have suicide-related behavior during the 30 days prior to AED exposure than at any other time period in the year before and after exposure, even after controlling for psychiatric comorbidity.
- There were 106 SRB events among 92 Veterans in the year after exposure, with approximately 22% (n=16) of those Veterans also having an SRB event before their first AED exposure. Moreover, the rate of SRB after starting on an AED was gradually reduced over time.
- The majority (76%) of those prescribed a first AED monotherapy received gabapentin (n=68,725), with Valproate (n=5,833) the second most common AED.
LIMITATIONS:
- This study combined suicidal ideation and attempts. Investigators did not have data on suicide completion, which is substantially more rare than suicidal ideation or attempt.
- Use of administrative data may have limited the investigators' ability to identify all cases of SRB.
- This study did not include patients on multiple AEDs.
IMPLICATIONS:
- Results suggest that the peak in suicide-related behavior is prior to AED exposure. However, as the risk for recurrent SRB was 22% in individuals with SRB prior to exposure to AED therapy, these Veterans should be followed closely to prevent recurrent SRB.
AUTHOR/FUNDING INFORMATION:
This study was funded by HSR&D (IIR 06-062). Drs. Pugh and Wang are part of the South Texas Veterans Healthcare System.
Pugh MJ, Hesdorffer D, Wang CP, et al. Temporal Trends in New Exposure to Antiepileptic Drug Monotherapy and Suicide-Related Behavior. Neurology November 26, 2013;81(22):1900-1906.
