Health: U.S. Experts Mull Flu Drugs, Abnormal Behavior Link

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U.S. Experts Mull Flu Drugs, Abnormal Behavior Link

 

Tue Nov 27, 2007 1:38pm EST

 

By Kim Dixon

http://www.reuters.com/article/healthNews/idUSN2747283820071127?feedType=nl & feed\

Name=ushealth200

 

GAITHERSBURG, Maryland (Reuters) - The safety of influenza drugs is

under scrutiny as advisers to the U.S. Food and Drug Administration on

Tuesday analyzed abnormal psychiatric behavior seen in some patients,

especially children.

 

Medical experts are reviewing cases of patients taking Roche Holding

AG's Tamiflu and GlaxoSmithKline Plc's Relenza experiencing

hallucinations, delirium and other abnormal behavior. In the case of

Tamiflu, several cases resulted in erratic behavior, including jumping

from buildings, resulting in death.

 

It's the third time health officials are publicly discussing flu drug

safety, originally prompted by reports two years ago of a dozen

deaths, including suicide, of children in Japan who had been taking

Tamiflu.

 

Japan in March warned against prescribing Tamiflu to those ages 10 to

19 when more than 100 people, mostly young, showed signs of strange

behavior after taking the drug. It also broadened its probe to other

flu drugs, Relenza and amantadine, after additional reports of

abnormal behavior.

 

FDA staffers are recommending a stronger label warning for Tamiflu to

note patient deaths and suggest close monitoring children for

behavioral changes. For Relenza, addition of a warning about

hallucinations and delirium is recommended.

 

Although there is still no evidence of a direct link, the contribution

of the drugs cannot be ruled out, FDA safety reviewer Dr. Adrienne

Rothstein told the panel, which will vote later on Tuesday on whether

to beef up labeling warnings.

 

Known generically as oseltamivir, Tamiflu is a pill, while Relenza,

generically known as zanamivir, is inhaled. Makers of both drugs have

stood by their safety, citing no direct evidence of cause and effect.

 

Two earlier FDA panels found no evidence of a direct link between

Tamiflu and the deaths, although the FDA did ultimately update

Tamiflu's label to add a caution urging close monitoring of patients

for abnormal behavior such as delirium or self- injury. Relenza's

label has no such warnings.

 

About 48 million people have taken Tamiflu worldwide, including 21

million children, since approval in 1999, according to Roche. Relenza

is much less widely used, by about 4 million people since its launch

in 1999.

 

The Japanese have adopted the drug much more broadly than the United

States, with a large majority of the worldwide use of Tamiflu

occurring in Japan.

 

Tamiflu had lackluster sales as a drug to prevent and treat seasonal

flu, but got a second life when it was the first drug to show real

efficacy in fighting a strain of bird flu that raised fears of a human

pandemic. Since then, Tamiflu has been stockpiled by governments

preparing for a potential flu pandemic.

 

The influenza virus is a major cause of death and illness in the

United States. Complications from the viral illness kills about 36,000

people a year in the country, a government expert told the panel.

Children and seniors are especially at risk.

 

Four drugs are approved for influenza, but generics amantadine and

rimantadine are no longer recommended for use as many strains of the

virus are resistant to them.

 

(Reporting by Kim Dixon; editing by Andre Grenon)

 

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