Attention deficit hyperactivity disorder (ADHD) drugs did not increase the risk for cardiovascular (CV) events among children, data from a retrospective cohort study involving more than 1.2 million children and young adults indicate.
William Cooper, MD, MPH, of Vanderbilt University in Nashville, and colleagues found no increased risk for sudden cardiac death, stroke or MI among younger current or former ADHD medication users compared with the general population.
However, the upper limits of the 95% confidence intervals for current and former users “indicated that a doubling of the risk could not be ruled out,” the researchers wrote in the New England Journal of Medicine, noting that the “absolute magnitude of such an increased risk would be low.”
The study was performed after adverse CV event case reports among children taking these medications in Canada and the United States prompted the FDA to propose label changes that would warn about sudden cardiac death risk, and the American Heart Association to deem it “reasonable” to perform echocardiography among children taking ADHD medications.
The AHA revised their statement and the FDA scrapped the label changes this past April, when preliminary results from several studies investigating the association between ADHD medications and CV events became available. Currently more than 2.7 million U.S. children take ADHD medications each year.
Cooper and colleagues analyzed data from 1,200,438 children and young adults ages 2 to 24 years from four health plans — Tennessee Medicaid, Washington State Medicaid, Kaiser Permanente California, and OptumInsight Epidemiology — among whom a total of 81 serious cardiovascular events occurred. These included 33 sudden cardiac deaths, nine acute MIs and 39 strokes.
There were seven events during 373,667 person-years of current ADHD drug use, 25 events in 607,475 person-years for former users, and 49 events during 1,597,962 person-years among non-users.
Neither former nor current ADHD medication use was associated with increased risk for serious CV events (HR=0.75, 95% CI: 0.31-1.85; and HR=1.03, 95% CI: 0.57-1.89, respectively), the researchers found. Furthermore, no risk was identified when current users were compared with former users.
Study limitations included the low number of events, which limits its statistical power, particularly for individual endpoints and drugs.