The research behind why drugs have become less effective - and how new drugs might take their place is being studied by scientists at the National High Magnetic Field Laboratory and Institute of Molecular Biophysics at Florida State University and researchers at Brigham Young University in Utah.
"Resistance to drugs is a fundamental problem that develops from their misuse, overuse and underuse," said Timothy A. Cross.
Compounding the problem is that "the development of new drugs to take their place is a decade-long process with infrequent success."
Two of the four antiviral drugs used to treat a nasty case of the influenza A virus no longer work. The protein, called the M2 channel, plays a key role in the virus' ability to reproduce. But the M2 channel mutated just enough to allow the virus to resist both drugs.
Detailed MRI scans allowed the researchers to chart the tiniest, previously unknown aspects of the protein's atomic structure.
"Now that we have a much more refined view of M2 - going all the way down to the atomic level, the level that includes protons going through the channel - we can draw conclusions about how to block it," said David Busath, a biophysicist at Brigham Young University.
Busath and his team have already begun screening millions of compounds, looking for drugs that will bind to the channel and block its reproductive role.
As to why the longtime flu drugs have become ineffective, the massive misuse of amantadine in poultry may have played a role, Cross said.
"It's terrible to utilize these miracle drugs that can save thousands, if not millions, of lives and dramatically reduce hospitalizations in that fashion," Cross said.
The study has been published in the journal Science.