ADHD drugs could cause irregular heartbeat

By Caleb Radford / 2nd of June, 2016

NEW research has found that a drug commonly used to treat Attention Deficit Hyperactive Disorder (ADHD) can increase the risk of an irregular heartbeat in children.

Researchers from the University of South Australia found that some children who had been prescribed with the ADHD medication methylphenidate (commonly known as Ritalin) were at high risk of developing arrhythmia.

The study was conducted with the help of the South Korea National Health Insurance Database where more than 100,000 children with ADHD aged 17 or younger were studied.

More than 1000 cardiac events were recorded over the study period, which compiled data from 2008 to 2011.

Senior Research Professor at the University of South Australia’s Sansom Institute for Health Research Libby Roughead said although the risks were still relatively low, they did exist.

“We were looking at what were the adverse events more common in children after they started using the medicine than these same children were before they had the medicine or after they took it,” she said.

“What we showed was that there is an increased risk of arrhythmia, so an unusual heart rhythm and this is more pronounced in children who have existing cardiovascular disease or are on some other medicines that can also affect the heart.

“What parents should know is that they should monitor simple things like blood pressure and heart rate after taking the medicine and before. If they start to feel nervous they should talk to their doctor.”

Cases of arrhythmia were statistically significantly more likely to have occurred during the first two months of using methylphenidate compared with periods of non-use, and the risk was highest in the first three days of use.

More than 6 million children in the United States between the ages of 4-17 have been diagnosed with Attention Deficit Hyperactive Disorder.

Children with ADHD demonstrate little control over impulses and may have trouble paying attention.

Methylphenidate is one of the most common ADHD medications and includes the brands Metadate, Concerta, Daytrana and Ritalin.

They are stimulants and work to block the reuptake of norepinephrine and dopamine into neurons to improve concentration while decreasing fatigue. Stimulants like methylphenidates are often the first choice of medication used for ADHD treatments.

Prof Roughead said the study was observational and should be interpreted with caution.

“With the global increase in the use of drugs for ADHD, the benefits of methylphenidate should be carefully weighed against the potential cardiovascular risks of these drugs for children and adolescents,” she said.

“What I think the study underlines is the need to consider the severity of ADHD symptoms and the option of non-stimulant treatments for children with high cardiovascular risk.”

The collaborative research included teams from McGill University and the Jewish General Hospital in Canada, Seoul National University in Korea and the School of Pharmacy at the University of South Australia.

The study titled Cardiovascular safety of methylphenidate among children and young people with attention-deficit/hyperactivity disorder (ADHD): nationwide self controlled case series study was published in the British Medical Journal.

South Australia’s capital Adelaide has three long-standing public universities, Flinders University, University of South Australia, and the University of Adelaide, each of which are consistently rated highly in the international higher education rankings.

The Sansom Institute for Health research is a consortium of leading researchers with the aim of intervening early to prevent illness, improve health systems and services, creating more effective therapies and advancing health equality.