Experts Urge Stern ADHD Drug Warnings
Surprise Vote Follows Preliminary Study Suggesting Risks
Preliminary Study of Risks continued...
A study of approximately 676,000 patients found an elevated occurrence of heart attacks and strokes in adults taking ADHD drugs, including Adderall, Ritalin, and Concerta. Children on the drugs also showed a higher-than-expected number of strokes, though their rate of heart attacks was lower than expected.
Strattera, another drug used to treat ADHD, is not a stimulant but was also included in the study. The expert panel did not include Strattera in their recommendation to add a warning.
In all, the study found 49 cases of heart attacks in children and adolescents who had taken ADHD drugs. That's compared with 12 attacks expected in that age group, based on national health data.
In adults, 732 heart attacks were observed where only 218 were expected, and 401 strokes occurred where 164 were expected.
Researchers stressed that the findings were preliminary and, at this point, theoretical. The study did not determine whether or not patients were actually taking ADHD drugs when they died. It also did not account for existing health conditions or other drugs patients may have been taking.
"There's smoke. Does that mean there's fire, or not?" said David Graham, MD, an FDA safety reviewer who conducted the study. "Our concern is enough to motivate us to want to nail down the uncertainty."
The FDA has received about 20 reports of sudden deaths in adults and children taking Adderall, the most popular stimulant medication for ADHD. Those reports prompted the Canadian government to order Adderrall XR, the drug's extended-release form, off the shelves last February. The drug was returned to pharmacies over the summer with new safety warnings.
More than 4% of children and adolescents -- an estimated 2.5 million in total -- take stimulant drugs for ADHD. More than 1 million prescriptions are written each month for adults, a market that has nearly doubled in the last four years.
Todd Gruber, MD, vice president of Ritalin manufacturer Novartis, said his company has reviewed more than 50 years of side-effect reports stemming from Ritalin.
"There does not appear to be any increase in cardiovascular events associated with methylphenidate [Ritalin] use when viewed in the context of rates in the general population," Gruber told the committee.
Matt Cabrey, a spokesman for Shire Pharmaceuticals, which makes Adderall, said the company believes its current label is appropriate. "Our goal is to ensure that patients and physicians have all the information they need," he said.
Panel: Don't Wait to Warn
Adderall and Adderall XR already carry boxed warnings alerting patients to the potential for abuse and that overuse can lead to heart attacks and strokes.
But several experts said the FDA should not wait for the results of a new FDA study to warn the public about the risk. Several also recognized that their actions were drastic.