The World Health Organisation on Friday endorsed findings that there is no clear evidence that the antiviral Tamiflu prevents complications such as pneumonia in otherwise healthy people with seasonal flu.

But WHO continues to recommend that the drug, made by Swiss drugmaker Roche, be used immediately in people infected with the separate H1N1 swine flu virus who are at high risk of complications or whose symptoms persist for 3 days or worsen.

An updated review of past clinical trial results by researchers from the Cochrane Review, published by the British Medical Journal on Tuesday, found there was insufficient data to know if the drug cut complications from flu in otherwise healthy patients.

“We would not take issue with the Cochrane conclusions concerning seasonal influenza,” WHO spokesman Gregory Hartl said.

Hartl told Reuters: “That is entirely consistent with our views and guidelines. For otherwise healthy people presenting with uncomplicated seasonal influenza, they do not need to be treated with the drugs.”

Roche has contested the finding and said it stood behind the previous data showing a benefit.

At issue is whether or not certain previously published trials on Tamiflu should be included or excluded when analysing the drug’s effectiveness.

Governments around the world have stockpiled Tamiflu, known generically as oseltamivir, to fight swine flu. H1N1 virus emerged in April and started an influenza pandemic which has killed at least 8,768 people.

“We need to make very clear that what Cochrane was looking at was seasonal influenza, it was not H1N1,” Hartl said.

In the course of the H1N1 pandemic, “a substantial body of evidence has been building up to indicate oseltamivir is effective at reducing and/or preventing severe illness and even death,” he added.

This was mainly in people who are at higher risk from H1N1 due to underlying medical conditions such as asthma or in patients who develop severe illness, he said.

“So our recommendations have been and continue to be that concerning infections with H1N1, if you are in a high risk group you should start oseltamivir treatment immediately.

“If you are not in a high risk group but if you have symptoms which persist over 3 days and or get worse, you should begin oseltamivir treatment.”

Otherwise healthy individuals do not need to be treated with Tamiflu, as the great majority of H1N1 patients recover without any kind of medical care, the WHO spokesman said.

The pill competes with another less widely used flu medicine from GlaxoSmithKline, called Relenza and known generically as zanamivir, which must be inhaled.

SOURCE: BMJ, December 9, 2009.
By Stephanie Nebehay