Ritalin and similar forms of ADHD medication may trigger abnormal heart rhythms and increase heart attack risk in some children soon after they start taking the drug, according to a new study.
This connection was especially true for children who were born with heart disease.
According to the study, published in the British medical journal BMJ, kids had an increased risk of heart attack between eight and 56 days after starting methylphenidate, a stimulant most commonly sold as Ritalin, although this heightened risk didn’t reach statistical significance. The researchers could find no evidence of a heightened risk for stroke, high blood pressure or heart failure.
What we knew before:
Past population-based studies have found no link between methylphenidate and heart attack or stroke in children, although some researchers have hypothesized that because the absolute number of kids who suffer these events is so small, these past studies didn’t have enough statistical power to observe any relationship between medication and cardiovascular events.
Meanwhile, case studies linking methylphenidate to individual cases of heart failure continue to surface, raising concern about the medicine’s negative effect on cardiovascular health.
The study details:
A group of researchers from Australia, Canada, and South Korea queried South Korea's nationalized health insurance database, which contains diagnoses and prescription information for 50 million Koreans. They pulled data on kids under 17 who had been diagnosed with ADHD and subsequently started taking methylphenidate.
They also looked at whether these children had at least one adverse cardiovascular event (arrhythmia, hypertension, heart attack, stroke or heart failure) between 2008 and 2011. In total, they examined 1,224 cardiac events in a population of 114,647 kids who had been diagnosed with ADHD and newly treated with the medicine.
They then calculated the length of time between first exposure to the medicine and the cardiovascular event, and found that arrhythmia was 61 percent more likely to occur some time during the first two months after starting methylphenidate compared to periods when kids didn’t use the drug. And while it didn’t rise to statistical significance, kids were also more likely to have heart attacks one week after starting medication. This heightened risk period lasted for two months.
The most current report is still observational, which means scientists can’t say for sure that the medicine caused these cardiovascular events. They can, however, demonstrate a link between the two.
What experts say:
While this study is definitely concerning, it’s important to remember the absolute risk of arrhythmia or other cardiovascular events is very small -- among average children, only 3 in 100,000 will suffer one -- and thus any additional risk that methylphenidate could contribute also remains small. In the U.S., an estimated 3.5 million kids take a stimulant drug, usually methylphenidate, for ADHD.
In an op-ed published alongside the study, epidemiologist John W. Jackson of the Harvard T.H. Chan School of Public Health writes that the study also serves as a reminder to parents to add family and medical history to their list of considerations when deciding to medicate a child. This is especially true for kids with congenital heart disease, Jackson wrote.
Currently, the Food and Drug Administration already warns patients and parents of children with ADHD that those with a personal or family history of heart problems should talk to their doctor before taking the medication, and that those who are on it should have their blood pressure and heart rate checked regularly.
How this could affect you:
If your child has been diagnosed with ADHD, be sure to discuss in full with a doctor the severity of his or her disorder, along with the possible risks that come with methylphenidate, Jackson warns. Parents of kids who already have some degree of heightened cardiovascular risk should consider non-stimulant options, he concludes.
Some non-medicated ways to treat ADHD in children include behavior therapy, counseling, social skills training and skills training for the parents, according to the Mayo Clinic. Other less-researched options include yoga, meditation, diets and exercise, although a new study recently suggested that a "healthy lifestyle" that includes daily physical activity, nine to 11 hours of sleep and limits on added sugar could make a positive difference in children who have been diagnosed with ADHD.