ADHD drug warnings could cause undue worry-doctors

BOSTON, Mar 22 (Reuters) New warnings that may be added to drugs for attention deficit disorder, or ADHD, could have a chilling effect on prescribing habits of doctors, cut sales of the drugs and create unnecessary fear in the public, some experts say.

This week a US Food and Drug Administration advisory panel will meet to discuss potential cardiovascular and psychiatric side effects of drugs such as Novartis AG's Ritalin, Johnson&Johnson's Concerta, Shire Pharmaceuticals Group Plc's Adderall and Eli Lilly&Co.'s Strattera.

The FDA panel, a group of outside experts, will also consider the possible increased risk of suicidal thinking with Cephalon Inc.'s experimental treatment Sparlon, a drug containing the same ingredient as its narcolepsy treatment Provigil. Cephalon's stock has fallen 11 percent since March 15, when it was revealed that Sparlon's risks would be scrutinized during the discussion of ADHD drugs and suicide risk.

A different FDA advisory panel that met last month recommended that the ADHD drugs carry black box warnings -- the most serious possible -- about the potential risk of sudden cardiac death and heart attack. Adderall already carries such a warning.

The panel that meets today will consider whether and how to strengthen warnings about the cardiovascular risks, as well as psychiatric risks such as psychosis and mania.

FDA officials say they are waiting to hear from the panel before deciding whether new warnings are needed.

''The reaction at the FDA is more emotional and political than scientific,'' said Dr. Joseph Biederman, chief of pediatric psychopharmacology at Massachusetts General Hospital and Professor of Psychiatry at Harvard Medical School. ''These drugs in healthy people have an extraordinary record of safety.'' ''The vast majority of the risks are known, understandable and controllable,'' said Dr. F. Xavier Castellanos, professor of Child and Adolescent Psychiatry at New York University School of Medicine and author of ''Stimulant Drugs and ADHD Basic and Clinical Neuroscience.'' ''If they put black boxes around everything, they will cease to have any relevance,'' he said.

Attention deficit hyperactivity disorder is characterized by impulsivity, lack of focus and hyperactivity. Every month US doctors write 2 million prescriptions for ADHD drugs for children and another 1 million for adults.

Dr Steven Nissen, a cardiologist at the Cleveland Clinic and a member of the panel that recommended stronger heart risk warnings, said last month he wanted a doctor's hand to ''tremble'' a little before writing a prescription for ADHD drugs.

Some analysts think strengthening of safety warnings on the drugs is inevitable.

''The FDA clearly wants to make material changes to the labeling for the ADHD class of drugs,'' said Marc Goodman, an analyst at Morgan Stanley. Goodman recently cut his growth rate prediction for the ADHD market to 5 per cent from 7 per cent for the 2006 to 2010 period.

The debate over ADHD drugs comes on the heels of a similar debate over the use of the SSRI class of antidepressants, which some claim increase the risk of suicidal thoughts among adolescents. In 2004 the FDA required antidepressant makers to include that risk in a black box warning.

''That hasn't helped anyone much,'' said Barbara Ryan, an analyst at Deutsche Bank. ''We're in an environment now where labels are becoming so riddled with warnings that people don't know what to do.'' REUTERS PR PM0859