Children taking stimulant drugs like Ritalin for ADHD aren't at greater risk of having a heart attack or other serious cardiovascular problems, according to new research published online today in the New England Journal of Medicine.
But critics of the widespread use of prescription amphetamines to treat the symptoms of attention deficit-hyperactivity disorder — 2.7 million children are taking the drugs — say this latest study still doesn't give ADHD drugs a clean bill of health.
"It helps a little bit, but doesn't help all that much," says Steven Nissen, chairman of the department of cardiovascular medicine at the Cleveland Clinic.
In this new study, the researchers looked at the medical records of 1.2 million children and young adults in four health plans in time frames from 1.5 to 3.9 years. They found that 81 had heart attacks, strokes, or died suddenly while taking methylphenidate, sold under the brand name Ritalin. That translates to three serious problems for every 100,000 years people took the drug. That risk was the same as for people of the same age who weren't taking Ritalin.
But because so few people had serious problems, it was impossible for the researchers, led by Dr. William Cooper at Vanderbilt University, to nail down the exact risk. It could be as much as double for children taking stimulant drugs. "Well, how reassuring is that?" Nissen tells Shots. "That's a long way from saying these drugs are safe."
The new study, funded by the U.S. Food and Drug Administration and the Agency for Healthcare Research and Quality, also didn't look at less serious issues, such as heart palpitations and irregular heart beats. Nissen says those are common problems in children taking stimulants. Stimulant drugs increase heart rate and blood pressure, so such problems wouldn't be surprising.
Cardiologists, pediatricians, federal regulators, and parents have been wrestling with this question for years. In 2007, the FDA told drug manufacturers they needed to warn patients of the risk of serious cardiovascular events in the labels for Ritalin and other stimulant drugs. The concern stemmed from FDA data collected from 1999 through 2004, which found that 19 children taking prescription stimulants for ADHD had died suddenly. Another 26 had strokes, heart attacks and/or heart palpitations.
In 2008, the American Heart Association recommended that all children have an electrocardiogram to check for heart problems before being prescribed ADHD stimulant drugs. Members of the American Academy of Pediatrics balked, saying that requiring ECGs for millions of children was unnecessary. The two groups subsequently reached a compromise, saying pediatricians should do a careful family history, and then make their own judgment about whether a child needs an ECG before being prescribed stimulant drugs.
Today's study may reassure parents, but Nissen says that too many children are being prescribed stimulant drugs unnecessarily. "Many of us are concerned about the massive overuse of these drugs," he says. "In some schools 10 to 12 percent of 6th-grade boys are taking these drugs. That doesn't strike me as being a very sound public policy."
Recently, the American Academy of Pediatrics issued controversial guidelines for doctors that say kids as young as 4 can be diagnosed and treated with ADHD medicines. The FDA hasn't approved use of the medicines in children younger than 6.
Nissen says that parents and doctors should make sure that stimulant drugs are given only to children with serious behavior problems; that they are given at the lowest possible dose; and that children are taken off the drugs as soon as possible.