Asia to test injectable drug for bird human flu

HONG KONG - A new anti-viral drug to treat both bird and human flu, developed by U.S.-based BioCryst Pharmaceuticals, will be tested across Asia next month, the pharmacist involved in the trial in Hong Kong said on Monday.

In an earlier animal trial, the drug, peramivir, boosted the survival rates of mice and ferrets infected with the H5N1 bird flu virus. Some experts say it could be the next-line drug to fight all types of influenza, including H5N1.

The trial will involve people seeking treatment for seasonal influenza in Hong Kong, Singapore, New Zealand and Australia. Half of them will be given peramivir, and the other half a conventional, orally-administered flu drug.
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Peramivir is a parenteral, or intravenous, anti-viral drug.

“They (BioCryst) will compare which (drug) is better, parenteral or oral, to see which one cures faster, which (type of administration) brings viral loads down faster,” said William Chui of the University of Hong Kong’s Clinical Trials Center.

Roche Holding AG’s Tamiflu is considered the first line of defense against bird flu, although early treatment — within 48 hours of the first signs of symptoms — is pivotal.

Injected drug more effective
A death rate of up to 60 percent has spurred the search for other drugs and vaccines to fight the H5N1 strain, which experts fear could cause a pandemic if it ever becomes easily transmittable among people.

“In a pandemic, having an oral treatment may not be enough because intravenous treatment is more efficacious,” said Chui.

“Having the drug injected means it goes straight to the bloodstream ... so if you administer at the 48th hour, the body can still benefit, but an oral dose will take time to get into the blood. There will be a time lag,” Chui explained.

“You have to be fast if you want to curb viral replication. Once after 48 hours, the viral load will be very high, and it will be very tough (to get rid of them).”


The development of peramivir may be an answer to experts who want to have several antivirals to choose from in fighting all types of flu because the viruses mutate quickly.

“We have seen resistance against Tamiflu in Japan where doctors dispense the drug (to fight seasonal human flu) very freely. It is time to find new treatments,” Chui said.

Relenza, made by GlaxoSmithKline, is an inhaled drug regarded as capable of treating both bird and human flu.

Vitamin C no help in stopping, shortening colds

For the average person, popping vitamin C pills is unlikely to ward off the common cold or shorten its length or severity. However, for people exposed to short bouts of extreme physical exercise or cold temperatures, vitamin C may markedly reduce their risk of catching a cold.

The findings stem from a review of 30 published studies involving 11,350 people who took at least 200 milligrams of vitamin C each day.

Based on pooled data, regular ingestion of vitamin C did nothing to lower the risk of the common cold in the ordinary population, report reviewers in the latest issue of The Cochrane Library, a publication of the Cochrane Collaboration, an international organization that evaluates medical research.

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There was a slight reduction in the duration and severity of common cold symptoms with vitamin C, compared with placebo, but the magnitude of the effect was so small its clinical usefulness is doubtful, the experts report.

Therefore, it is senseless for most people to take vitamin C every day to reduce their risk of catching a cold, according to co-author Harri Hemila of the University of Helsinki, Finland and her colleagues.

An exception appears to be when individuals are exposed to short periods of extreme physical stress. In six trials involving a total of 642 marathon runners, skiers, and soldiers taking part in sub-arctic exercises, vitamin C supplements reduced the risk of the common cold by 50 percent.

Vitamin C, for the average person, also failed as a ”therapeutic” for the common cold. Trials of high-dose vitamin C taken after the onset of cold symptoms showed “no consistent” effect on either the length of a cold or the severity of symptoms.

Hemila and colleagues caution that there were only a few therapeutic trials and their quality varied. One trial showed a borderline benefit from downing an 8-gram dose of vitamin C at the beginning of a cold, and two trials using 5-day supplementation reported benefits.

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More trials testing vitamin C as a possible treatment for the common cold are needed, the reviewers conclude.

The value of vitamin C in preventing and treating the common cold has been the subject of controversy for six decades. Nonetheless, vitamin C is widely sold and used for these purposes.

The authors of the Cochrane report conclude, based on the data at hand, that the routine use of vitamin C to prevent the common cold is “not rationally justified for community use. It could be justified in people exposed to brief periods of severe physical exercise or cold environments.”