Panel: ADHD drug warnings unneeded

Food and Drug Administration advisers recommended Wednesday that drugs like Ritalin used to treat attention deficit hyperactivity disorder don’t have to carry strong “black box” warnings about possible cardiovascular and psychiatric risks.

An FDA advisory committee’s decision breaks ranks with another committee, which voted last month to include the warnings on the drug labels. Wednesday’s decision recommends that the drug labels be written more clearly so people can understand them.

Some experts said adding the warnings to the drugs – which include Adderall and Strattera – could do more harm than good.

Nearly 3.3 million Americans age 19 and younger used an ADHD drug last year, according to Medco Health Solutions Inc., a prescription drug benefit program manager.

WASHINGTON

Scientists unravel avian flu virus

Two research teams have independently discovered explanations for the chief features of the H5N1 bird flu virus – its difficulty infecting humans, and the deadly effects when it does.

Unlike influenza viruses that are passed easily between people, H5N1 has a hard time attaching to cells in the nose, throat and upper airways. However, it readily attaches to cells deep in the lungs.

This suggests that people need close and heavy exposure to the H5N1 virus for it to get into the lungs, where it can take hold. But once there, it causes extensive damage to the machinery of respiration – the cells and air spaces where oxygen is exchanged for carbon dioxide. That scenario closely mimics the clinical experience of many of the 184 human cases of bird flu that have been officially diagnosed and recorded since late 2003. More than half of those have been fatal.

One research groups published its results in Wednesday’s issue of the journal Nature, and the other online in the journal Science.

Fluoride limits called too high

Government limits on fluoride in drinking water aren’t protecting the public from possible tooth and bone damage, according to a prestigious advisory panel.

The Environmental Protection Agency allows so much fluoride that some children in areas with unusually high natural fluoride levels are developing discolored teeth and weakened tooth enamel, according to the report from the National Academies’ National Research Council.

The council notes that municipalities in areas with low or no fluoride in their water add low levels of the compound to drinking water to help prevent tooth decay, but water supplies in some areas have much higher amounts of naturally occurring fluoride. Industrial pollution also can increase the levels.

The EPA’s ceiling on fluoride in drinking water is 4 milligrams per liter, or 4 parts per million. That’s four times the concentration recommended to fight cavities, which is between 0.7 and 1.2 parts per million, according to the American Dental Association.

DUBLIN, Ireland

Decision delayed on MS drug Tysabri

The Irish and U.S. manufacturers of a suspended multiple sclerosis drug said Wednesday that American regulators have delayed until June their decision on whether to permit Tysabri to return to the market.

In a joint statement, Elan Corp. PLC of Ireland and Biogen Idec Inc. of Cambridge, Mass., said the Food and Drug Administration had extended the time it would take to reach a verdict from next week until late June.

The FDA in November 2004 approved Tysabri for sale to the approximately 350,000 people in the United States who suffer from MS. But Elan and Biogen withdrew the drug three months later when three people taking Tysabri in trials contracted a rare brain disease. Two died.

Compiled from wire reports