9 January 2009
US Scientists have revealed that excessive antiviral drug can accelerate drug resistance in viruses, and that resistance can spread rapidly
Overuse of cheap and popular drugs like Tamiflu may make the avian flu virus resistant to it. Scientists in the US have warned against their use after their failure to stop the flu virus in Asia.
The scientists say that excessive antiviral drug can accelerate drug resistance in viruses, and that resistance can spread rapidly, reports IANS.
The results should serve as a warning to those who consider Tamiflu the great antiviral medication, researchers warned.
Researchers analysed almost 700 genome sequences of avian influenza strains to document where and when the virus developed resistance to a class of antiviral drugs called adamantanes and how far the resistance spread.
In order to prepare for a long–feared pandemic flu outbreak, especially in the event that avian flu mutates enough to infect and be easily transmitted among humans, Tamiflu has become a standard to avoid it.
“We can’t necessarily say what we’ve seen in adamantanes is predictive of what will happen with Tamiflu. But in the larger dynamic, perhaps it serves as a cautionary tale,” said Daniel Janies, study co–author and an associate professor of biomedical informatics at Ohio State University.
Seasonal Influenza in Asia had developed resistance against the antiviral drug adamantanes and this was discovered in 2002 but by 2006 the drug was declared worthless as a treatment for the flu because more than 90 percent of the strains had developed a resistance to the drugs, an Ohio release said.
Janies analysed hundreds of avian flu genomes isolated from avian, feline and human hosts between 1996 and 2007 and found that every third of the samples carried mutations enabling the virus strains to resist the effects of adamantane drugs.