September 21, 2007

Study to examine heart-related risks of ADHD drugs

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William Cooper, M.D., M.P.H., is studying heart-related side effects in children who take various ADHD medications. (photo by Neil Brake)

Study to examine heart-related risks of ADHD drugs

Vanderbilt's William Cooper, M.D., M.P.H., has been named the principal investigator for the largest-ever review of possibly serious heart-related side effects in children who take medications for attention deficit hyperactivity disorder (ADHD).

Data for the study, which is being funded by the U.S. Agency for Healthcare Research and Quality (AHRQ) and involves three other sites, has been drawn from the insurance records of 10 million children in nearly every state, including nearly 300,000 who have been identified as having taken medications used to treat ADHD.

Cooper, associate professor of Pediatrics and director of the Child and Adolescent Health Research Unit, will lead the medical record review to see if rare cases of sudden cardiac death, heart attack and stroke are somehow associated with the medications.

ADHD medications are known to increase heart rate and blood pressure, but it is not known if that side effect directly or even indirectly might cause children to suffer heart attack or stroke.

The Food and Drug Administration had received a series of reports about these events occurring in children with exposure to ADHD medications.

However, the events are relatively rare, Cooper said.

“Because of the ability to identify large populations of persons through large health claim datasets, we anticipate being able to pull together a large enough sample from several locations across the country to identify whether a real risk exists,” Cooper said.

“One of the strengths of this work is the ability to build upon the important work in drug safety studies conducted by my collaborators, Dr. Wayne Ray and Dr. Marie Griffin, here at Vanderbilt over the past 30 years.”

As principal investigator, Cooper will draw on his own review of TennCare records and will combine that with data from three other sites to be analyzed at Vanderbilt. Investigators from each of the sites — which include Kaiser Permanente of California, the HMO Research Network and i3 Drug Safety, as well as scientists at AHRQ and the FDA — will be collaborating on the research.

The study has an adult component as well that is being coordinated elsewhere to review similar adult records for the same time period, 1998 to 2005.

The analysis will include all drugs currently marketed for treating ADHD, including the most popular: Concerta, Adderall and Strattera. Those three medications alone are ranked among the top five drugs prescribed for any child under age 17. A recent AHRQ analysis found $1.3 billion was spent on those drugs in 2004.

In May 2006, based on a review of anecdotal reports of sudden death, stroke and heart attack among patients taking usual doses of ADHD medications, the FDA asked drug manufacturers to revise product labeling to reflect concerns about possible adverse events. Drug manufacturers have created patient Medication Guides for individual products to help patients understand risks.

This massive data review, expected to take two years to complete will determine if further labeling changes, or some other safety action is needed, Cooper said.