Analyses of reports of death and injury suggest a possible link between ADHD drugs and cardiovascular problems, the FDA's Dr. Kate Gelperin told the advisory committee. But the link is not conclusive, nor is it clear whether there is an increased incidence of death or serious injury, she said.

The 8-7 vote, with one abstention, by the Food and Drug Administration committee was to recommend adding "black box" safety warnings to ADHD drugs. Doctors prescribe the increasingly popular drugs to about 2 million children and 1 million adults a month.

The FDA isn't required to follow the recommendations of its advisory committees but typically does.

May Be Linked to 25 Deaths

The federal agency originally had asked the scientific panel to consider ways of studying the drugs, which include amphetamines, such as Adderall, and methylphenidates, sold as Ritalin, Concerta, Methylin and Metadate.

The agency's own data suggested a link between the drugs and an increased risk of sudden death and serious cardiovascular problems, including heart attacks.

The panel quickly turned to a debate on whether it should consider new warnings for the drugs rather than simply discuss the need for more studies.

Panel member Dr. Curt Furberg said it would be "inappropriate, unethical behavior" for the FDA not to disclose to doctors and patients that there was uncertainty about the safety of ADHD drugs.

Dr. Steve Nissen told his colleagues they should push for the black box warning on the drugs' packages.

The drugs already bear warnings related to the possible risk they could pose to patients with heart defects, the FDA's Dr. Gerald DalPan said.

"We feel this warning is appropriate given our current knowledge of these drugs," he said prior to the votes.

The balloting on warning labels followed an earlier 15-0 vote to recommend that the FDA require that the drugs include a medication guide for patients and parents.

A federal health official said Thursday that there was a strong possibility the drugs may be linked to the deaths of 25 people.

"There's smoke. Does that represent a fire?" asked Dr. David Graham of the Food and Drug Administration.

Cardiovascular Problems Suspected

The deaths occurred between 1999 and 2003, according to an FDA report. Nineteen of them involved children. The report also detailed 54 cases of serious cardiovascular problems, including heart attack, stroke, hypertension, palpitations and arrhythmia, in adults and children being treated with ADHD drugs.

Some of these patients had pre-existing heart conditions or hypertension.

The FDA said it has tallied an additional 26 deaths between 1969 and 2003 in ADHD patients involving death by suicide, intentional overdose, drowning, heat stroke and from underlying disease.

The FDA's Drug Safety and Risk Management advisory committee was reviewing different ways to study whether the deaths were linked to use of the drugs. The few studies that have looked at longer-term use of ADHD drugs provide little information on those risks, the FDA said.

Analysis of the reports of death and injury suggests a possible link between the drugs and cardiovascular problems, the FDA's Dr. Kate Gelperin told the panel. But the link is not conclusive, nor is it clear whether there is an increased incidence of death or serious injury, she said.

That, Gelperin said, "is really a question we'd like to have answered."

Sales of $3.1 Billion in 2004

An FDA review found fewer than one death or serious injury per 1 million ADHD drug prescriptions filled, with one exception: 1.79 cases per million of nonfatal cardiovascular or cerebrovascular problems in adults treated with amphetamines.

Sales of ADHD drugs increased to $3.1 billion in 2004, from $759 million (€634 million) in 2000, according to IMS Health, a pharmaceutical information and consulting firm.

That stepped up use could spell increased risk.

"Because adults have a higher risk of heart disease and stroke to begin with, any increase in risk caused by these drugs could affect a large number of people," Graham said.

The FDA's Canadian equivalent, Health Canada, briefly pulled the ADHD drug Adderall XR from the market last year. A Canadian panel eventually concluded there was inadequate evidence of increased harm from the drug. The FDA reached a similar conclusion at the time.

Adderall is made by Shire Pharmaceuticals and Ritalin is made by Novartis Pharmaceuticals Corp. Various other companies make generic versions of Ritalin as well. ___ On the Net: Food and Drug Administration: http://www.fda.gov