Researchers at Simon Fraser University say they've found a way to improve on existing flu medications that are losing their effectiveness.

Virologist Masahiro Niikura and his doctoral student Nicole Bance are among an international group of scientists who have discovered a new class of molecular compounds capable of killing the influenza virus.

A study published last month in the journal Science describes how the modification of the approach used by flu treatments Tamiflu and Relenza could result in a new medication that is less likely to produce drug-resistant viral strains.

The new compounds are better at stopping the spread of a virus within the body because they firmly bind to an enzyme that the infection needs to replicate itself.

The new compounds are also more effective because they're water-soluble, according to Niikura.

"They reach the patient's throat where the flu virus is replicating after being taken orally," he said, in a press release. "Influenza develops resistance to Relenza less frequently, but it's not the drug of choice like Tamiflu because it's not water-soluble and has to be taken as a nasal spray."

Currently, the new compound is only available as a nasal spray, but Niikura said it will eventually be available in pill form.

Tests of the compounds have been done in the lab using mice, with contributions from researchers at the University of British Columbia, the B.C. Centre for Disease Control, the University of Bath in the U.K. and CSIRO in Australia.

Niikura said the next step is to test the drug using other viral strains to see if they mutate and develop resistance.

Influenza (flu) is an international health threat that affects millions of people and kills hundreds of thousands worldwide every year.

- with files from The Vancouver Sun