ADHD drugs get new scrutiny from the FDA
■ Troubling psychiatric and cardiac occurrences lead to drug label changes.
By Susan J. Landers — Posted Aug. 1, 2005
Washington -- Despite new safety concerns by the Food and Drug Administration about a commonly prescribed stimulant medication to treat children with attention-deficit/hyperactivity disorder, the drug should remain a treatment option, according to the agency.
The FDA's review of Concerta, a once-a-day form of methylphenidate, marketed by McNeil Consumer & Specialty Pharmaceuticals, a subsidiary of Johnson & Johnson, uncovered instances of troubling psychiatric and cardiovascular occurrences that will result in label changes regarding these safety concerns.
The company is committed to providing patients with safe and effective medications, said a representative for McNeil. They will work with the agency to evaluate any concerns about the drug, he said.
Meanwhile, the agency also is broadening its examination of post-marketing reports to include other stimulants approved for treating ADHD, as well as Strattera (atomoxetine) a nonstimulant manufactured by Eli Lilly and Co. The results of this FDA review likely will be brought before the agency's Pediatric Advisory Committee early next year.
The advisory committee heard the FDA's concerns about Concerta during its June 30 meeting.
For decades, physicians have been prescribing stimulants for patients with ADHD -- believed to affect 3% to 5% of all children, according to the National Institute of Mental Health.
Among the psychiatric events uncovered by the FDA's post-marketing review of children who took Concerta were suicidal thoughts, hallucinations, and psychotic behavior. Cardiovascular events included hypertension, fainting and arrhythmias.
The FDA's findings did not come as a surprise to many experts, who said the drug's label already warns of the possibility of increased blood pressure and psychosis. The drug is also contraindicated for those who have significant anxiety, tension or agitation.
The American Academy of Child and Adolescent Psychiatry cautioned its members about the limitations of the FDA's findings. The data, which were collected through the agency's MedWatch system, cannot show that an adverse event is caused by a particular drug, according to a statement presented to the advisory panel by Laurence Greenhill, MD, a New York child and adolescent psychiatrist on behalf of the AACAP.
Also, there may be underreporting of adverse events, since only the pharmaceutical industry is required to report all post-marketing adverse events, while such reports are voluntary for physicians who may also see them, Dr. Greenhill noted.
The number of adverse events also was very low. Of the approximately 1.2 million children prescribed stimulants during the FDA's review period from December 2003 to January 2005 -- about half of whom were prescribed Concerta -- only 20 children and adolescents reported having hallucinations, according to FDA documents.
"This means that one would have to treat over 60,000 children before encountering this adverse event, making it a rare adverse event," Dr. Greenhill said.
The FDA review uncovered 135 reports of the various events.
Despite the rarity of such events, physicians and parents should be on the alert for them, Dr. Greenhill said. Often a change in dose, time of administration or the medication itself was enough to resolve the problem.
The review of the drugs was partly triggered by differing approaches taken by Canadian and American health agencies when questions arose about the safety of Adderall, an amphetamine and popular treatment for ADHD, said Richard L. Gorman, MD, a pediatrician in Ellicott City, Md., and a representative for the American Academy of Pediatrics at the FDA advisory committee meeting. Adderall is a product of Shire US.
A review of post-marketing data led Canada to suspend sales of Adderall XR last February. The long-lasting form is the only version of the drug sold in that country. But a review of the same data led the FDA to opt instead for heightened warnings that patients with underlying heart defects might be at increased risk for sudden death from the drug.
At this point, Dr. Gorman intends to continue to prescribe Concerta and the other stimulants with all proper precautions in place. "When you make a diagnosis that you know you have an effective therapy for, you offer that effective therapy. You also advise those patients on the potential side effects of those medications."