The use of antiepileptic drugs may elevate risk for stroke in patients with Alzheimer’s disease, with the risk not changing based on antiepileptic drug type, according to a study published in the Journal of the American Heart Association.
“In our study among people with [Alzheimer’s disease], [antiepileptic drug] users had a 37% higher relative risk of any stroke than nonusers, and there were no differences among individual [antiepileptic drugs] or between older and newer [antiepileptic drugs],” Tatyana Sarycheva, MD, MSc, of the faculty of health sciences at the School of Pharmacy, University of Eastern Finland, and colleagues wrote. “The association was more evident with ischemic strokes than hemorrhagic ones partly because of the low number of hemorrhagic strokes in our cohort.”
To investigate the association between stroke risk and antiepileptic drug use in patients with Alzheimer’s disease, researchers used a nationwide register-based Medication Use and Alzheimer’s Disease (MEDALZ) cohort, which includes all Finnish patients who received an Alzheimer’s disease diagnosis between 2005 and 2011 (n = 5,167). Those who had previous strokes were excluded and, according to sex, age and time since Alzheimer’s disease diagnosis, researchers matched each antiepileptic drug user to a nonuser.
The mean follow-up was 351.7 days for users and 728.6 days for nonusers. During this time, 328 patients had a stroke, with a 2.75 incident rate (95% CI, 2.33-3.26) per 100 person-years among users and a 1.85 incident rate (95% CI, 1.61-2.14) among nonusers.
Researchers found that antiepileptic drug use was associated with a 37% increased risk for stroke compared with nonuse (HR = 1.37; 95%, 1.07-1.74) and that the risk was highest during the first 90 days of use (HR = 2.36; 95% CI, 1.25-4.47).
When stratified by stroke type, antiepileptic drug use was associated with ischemic stroke (HR = 1.34; 95% CI, 1-1.79) and there was a trend toward association with hemorrhagic stroke (HR = 1.44; 95% CI, 0.86-2.43).
In addition, researchers found that stroke risk was similar between users of older (including valproic acid, carbamazepine, clonazepam and phenytoin) and newer (including pregabalin [Lyrica, Pfizer], gabapentin, lamotrigine, oxcarbazepine, topiramate and levetiracetam) antiepileptic drugs (adjusted HR = 1.04; 95% CI, 0.71-1.53).
“Our results highlight caution in [antiepileptic drug] use in this vulnerable population, and such possible complication as a stroke should be kept in mind while prescribing [antiepileptic drugs],” the researchers wrote. – by Melissa J. Webb
Disclosures: Sarycheva reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.