WASHINGTON – Reports of sudden deaths, strokes, heart attacks and hypertension in both children and adults taking drugs to treat attention deficit hyperactivity disorder are spurring new government study into the medications' safety.
Sales of drugs to treat ADHD have increased sharply in recent years, with use growing at a faster rate among adults than children, according to a recent study by Medco Health Solutions, a prescription benefit manager. Spending on ADHD drugs soared from $759 million in 2000 to $3.1 billion in 2004, according to IMS Health, a pharmaceutical information and consulting firm.
The Food and Drug Administration said it had received reports of what it called "serious adverse events" — including deaths — in association with the therapeutic use of the drugs. No additional details on those events were immediately available.
The FDA's Canadian counterpart, Health Canada, yanked the ADHD drug Adderall XR from the market for six months last year in response to reports of 20 sudden deaths and 12 strokes in adults and children using the drug. A number of the cases involved children with structural heart defects.
The panel eventually concluded there was inadequate evidence of increased harm from Adderall XR compared with other available therapies — a conclusion the FDA also reached based on data on hand.
Now the U.S. regulatory agency is asking its Drug Safety and Risk Management advisory committee to examine ways of studying further the potential cardiovascular risks 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.
"It almost sounds like cox-2 inhibitor redux," said committee chairman Dr. Peter Gross, referring to cox-2 painkillers like Vioxx and Bextra pulled from the market because of evidence they can raise the risk of a heart attack or stroke.
The committee is to meet Feb. 9 and 10 in Gaithersburg, Md.
"The issue of drug treatment of attention deficit disorder in children has been a controversial one without this issue of cardiovascular risk too. It adds another concern to what will certainly be an interesting conversation," said Arthur Levin, the FDA committee's consumer representative.
A posting to the FDA Web site did not identify any of the drugs by name. However, the most commonly used ADHD drugs include Adderall XR, made by Shire Pharmaceuticals, and Ritalin, made by Novartis Pharmaceuticals Corp. Various other companies make generic versions of Ritalin as well.
Shire spokesman Matthew Cabrey said the company hadn't been told of the meeting but added it may send representatives. Novartis did not immediately return a call seeking comment.
The committee's Feb. 10 meeting will include updates on FDA actions on cox-2 drugs as well as a recently begun patient, doctor and pharmacist registry program for the anti-acne drug Accutane and its generic competitors.
Separately, the committee also will discuss the FDA's Drug Safety Oversight Board, an internal, government employee-only panel created nearly a year ago.
The board is supposed to monitor FDA-approved medicines once they're on the market and update physicians and patients with emerging information on risks and benefits.
Gross said he had concerns about the board's impartiality and independence, as well as its relationship to his committee and the very similar work it does.