Canada will be increasing its stockpile of antiviral drugs to protect against a possible ’flu pandemic, with additional purchases of Tamiflu and new purchases of the drug Relenza, the country’s chief medical officer of health said today.
Dr. David Butler-Jones told The Canadian Press some provinces have intentions to buy an additional five million pills—or 500,000 treatment courses—of the drug oseltamivir, sold as Tamiflu, over the next two fiscal years.
That would bring holdings in the country up to 40 million pills—enough drug to treat four million people if the current regime of two pills a day for five days is sufficient to combat the influenza strain that causes a future pandemic.
That will be augmented with Relenza, another neuraminidase inhibitor—the drug class to which Tamiflu belongs—as well as a small supply of an older, cheaper ’flu antiviral known as amantadine, Butler-Jones said.
“We’ll buy Relenza, as well. What percentage, I’m not sure.”
He also was not certain how much amantadine the country would buy. The drug is not effective at present against the H5N1 avian ’flu strain experts fear may be poised to trigger a pandemic.
And recently-published scientific data suggest human ’flu strains are increasingly becoming resistant to the drug, as well.
Relenza—the trade name for the drug zanamivir—is sold by GlaxoSmithKline.
Some antiviral experts believe the drug may be better for some people, including pregnant women, than Tamiflu because it goes directly to the site of infection and less drug is absorbed into the blood stream.
It does that because the drug is administered via an inhaler rather than in pill form.
While that gives it a biological advantage, it hasn’t been a popular feature among the drug-taking public and sales for the drug historically have been low. Consequently it has never been made in large amounts.
Butler-Jones said he felt the combination of the increased amounts of Tamiflu and the future purchase of Relenza would be adequate to meet the country’s treatment needs.
“In terms of mitigating the impact from a medical standpoint, we probably have enough now,” he said.
It previously had been thought the country had 22.5 million Tamiflu pills—enough to treat 2.5 million people.
Word of government intentions to purchase additional Tamiflu came as Roche Canada took the unusual step of halting sales through pharmacies to individuals , saying that shipments will end immediately until ’flu season begins.
The company has told pharmacies it has decided to “proactively manage the Tamiflu inventory” and it will “prioritize distribution of Tamiflu to those most at risk of developing serious influenza-related complications once the influenza season begins.”
