With more than 1.8 million children in the U.S. being treated annually with drugs for attention deficit hyperactivity disorder (ADHD), the possibility that such drugs could damage their hearts has been a significant cause of concern for parents and physicians alike.

Now, the results of a long-term National Institutes of Health (NIH)-funded study published last month in Pediatric Researchcould allay many of those concerns. The authors caution that because the study was conducted on primates, the findings are not automatically applicable to humans. However, they have previously published that this primate model reliably shows other side effects similar to what is found in children receiving these medications.

Cardiovascular Risks

Their new findings conclude that chronic exposure to methylphenidate (MPH), a commonly prescribed ADHD drug, is unlikely to increase cardiovascular risks in healthy children. "The findings are very reassuring in that even high-dose chronic MPH stimulant therapy did not result in any evidence of abnormal structures or function in the hearts of the monkeys," said Steven E. Lipshultz, MD, the study's principal investigator, and senior and corresponding author, who is the A.

Conger Goodyear Professor and Chair of the Department of Pediatrics in the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo. He also is the pediatric chief-of-service at Kaleida Health; medical director, pediatrics services business development, for John R. Oishei Children's Hospital; and president of UBMD Pediatrics.

The research was conducted while Lipshultz was the Batchelor Chair of Pediatrics and director of the Batchelor Children's Research Institute at the University of Miami Miller School of Medicine, and later while he was the Carman and Ann Adams Endowed Chair of Pediatric Research at Wayne State University School of Medicine and Children's Hospital of Michigan.

Sudden Cardiac Death Controversy

The results contribute important evidence to an ongoing controversy about whether or not MPH is associated with sudden cardiac death. A number of studies have reported an increase in sudden cardiac death or other damage to the heart in some children taking the drug or other stimulant therapy for ADHD.

With ADHD and related disorders diagnosed in about 10 % of all children in the U.S., and with as many as 70 percent of these children receiving stimulant prescription therapy, the question of possible cardiac risks has emerged as a major public health concern, Lipshultz said.