Children who take medicine for attention-deficit hyperactivity disorder aren’t at a higher risk for heart complications, according to a U.S.-funded study that suggests warnings placed on the drugs are unnecessary.
The pills include Adderall, made by Dublin-based Shire Plc (SHP); Ritalin, from Basel, Switzerland-based Novartis AG (NOVN); and Concerta, sold by Johnson & Johnson (JNJ), of New Brunswick, New Jersey. They’re used by more than 2.7 million American children.
In 2006, reports of heart attacks, strokes and sudden death in kids taking the medicines led U.S. regulators to urge that manufacturers warn parents and patients about the potential danger. In the latest study, reported today in the New England Journal of Medicine, no evidence of serious heart problems were found after researchers examined medical records for 1.2 million children and young adults covered by four U.S. health plans.
“We believe this provides a lot of reassurance about the safety of these medications,” said William Cooper, a professor of pediatrics and preventive medicine at Vanderbilt University in Nashville, Tennessee, and the lead researcher. “We found no increased risk for current users of ADHD medications.”
The study, funded by the Food and Drug Administration and the Agency for Healthcare Research and Quality, identified 81 heart attacks, strokes and sudden deaths in the study, with more among those taking the medicines than in a comparison group matched for age and gender who didn’t use the drugs.
There were seven events among patients taking the ADHD drugs, 25 in former users and 49 for those who had never been prescribed the medicines, the study found. The non-users were the largest group in the report, with researchers tracking the equivalent of 1.6 million of them each year. The seven heart complications seen among children taking the medications came out of the smallest group, composed essentially of 373,667 children followed for a year.
While there were fewer events in children taking the pills, the low number of complications overall made it hard to precisely determine the risk or rule out any drug involvement, the researchers said. It is still possible the drugs could contribute to cardiovascular complications, though the numbers would remain small, they said.
Patients treated for ADHD should continue taking their medicine as prescribed by their doctors, the FDA said today in a drug-safety update on its website. Stimulant drugs shouldn’t be given to heart patients, and everyone taking them should be monitored for changes in heart rate and blood pressure, the agency said.
Central Nervous System
Most ADHD drugs are central nervous system stimulants that can increase heart rate and blood pressure. Reports of heart problems in U.S. and Canadian children spurred the concern on use. The American Heart Association said it was reasonable to obtain an electrocardiogram in children starting the medicines, though that policy was later reversed, and several advisory panels for the FDA recommended strict warnings on the drug labels and packaging.
“People were really concerned and confused, which is why we wanted to do this study in the first place,” Cooper said in a telephone interview. “We think this study provides important information to guide policy makers, patients and their families about ADHD treatments.”
Four Health Plans
Health plans that contributed the data were Tennessee Medicaid, Washington State Medicaid, Kaiser Permanente in California and Optum Insight Epidemiology, a national private insurance health plan from UnitedHealth Group Inc. In all they found 3.1 serious cardiovascular events for every 100,000 children and young adults in the group each year.
The study, announced in 2007, was originally expected to take two years to complete. The FDA last July said the complexity of the review would delay results until early 2011. A separate analysis of adult patients is also being done.
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