No increase in severe cardiovascular
events for children and adolescents taking medication for ADHD
Despite recent concerns that medications for attention
deficit hyperactivity disorder (ADHD) could increase the risk of cardiovascular
events in children and adolescents, an observational study conducted by researchers
at the University of Pennsylvania School of Medicine and HealthCore Inc. finds
they are no more likely to die from a severe cardiovascular event than those who
do not take the drugs. The findings, published online in the journal Pediatrics,
provide the first analysis of such events in a large population of children and
adolescents receiving ADHD medications compared to non-users.
"These data provide reassurance that the thing most concerning - death
- is not any higher in users of ADHD medications than non-users," says senior
author Sean Hennessy, PharmD, Ph.D., an associate professor of Epidemiology at
Penn. "For kids who will benefit from ADHD treatment, the potential risk
of a cardiovascular event should not dissuade parents or caregivers from giving
a child or adolescent these drugs."
After previous studies found drugs to treat ADHD can lead to increased heart
rate and blood pressure in children, Hennessy's group turned to a large database
of patient records to see if patients who recently began taking ADHD medications
appeared any more likely to suffer from sudden death, myocardial infarction, or
stroke.
For the study, researchers sifted through patient data contained in Medicaid
databases from five states (CA, FL, PA, NY, OH) and the HealthCore Integrated
Research Database, which contains historical and current medical and pharmacy
claims data from more than 44 million enrollees in Blue Cross and Blue Shield
plans in 14 states. Hennessy's group identified 241,417 patients ages 3-17 on
ADHD medications and tracked their health records during the period they were
on medication (a median of 135 days). The researchers then compared rates of sudden
death, myocardial infarction, and stroke in patients taking ADHD medications to
those not taking medications who were of the same age, sex and from the same state
over a median of 609 days.
The researchers found 28 deaths in the group exposed to ADHD medications (incidence
1.79 per 10,000 person-years) and 607 in the control group (incidence 3.00 per
10,000 person-years). Additionally, the researchers identified no cases of myocardial
infarction or stroke in the group who received ADHD medications and 11 cases in
the unexposed group. Because the group of children and adolescents receiving ADHD
medications had no validated reports of stroke and myocardial infarction, researchers
were unable to rule out relative increases in the rate of such events from use
of the drugs.
"The fact that the rates of cardiovascular events that could be identified
were very low is of interest because at least we can tell that we do not have
an epidemic of such events in kids receiving ADHD drugs," Hennessy says.
"If ADHD medications were causing an epidemic of cardiovascular events, we
would expect to see it in this study."
"This is one of first answers but it won't be the last," Hennessy
says, adding that since 2007, the U.S. Food and Drug Administration (FDA) and
Agency for Healthcare Research and Quality (AHRQ) has been looking into the potential
cardiovascular risks of ADHD medications on children. "Until the results
of the FDA study become public, this study should provide reassurance to parent
and caregivers that ADHD drugs are safe from cardiovascular perspective."
Other authors of the study included Hedi Schelleman, Ph.D., Warren B. Bilker,
Ph.D., Brian L. Strom, M.D., M.P.H., Stephen E. Kimmel, M.D., MSCE, Craig Newcomb,
MS, James P. Guevara, M.D., M.P.H., all from Penn, and Gregory W. Daniel, R.Ph.,
Ph.D., M.P.H., and Mark J. Cziraky, PharmD, CLS, FAHA, all from HealthCore Inc.
The study was funded by Shire, a manufacturer of ADHD medications.
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