Researchers look to repurpose approved drugs to treat Zika virus

ATLANTA — The need for drugs to prevent and treat Zika infections grows with every new patient diagnosed. The virus causes devastating birth defects and is strongly linked to a type of paralysis called Guillain-Barre syndrome.

There are currently no approved drugs against Zika; developing a new medication for any disease can take 10 to 20 years.

"The sense of urgency is enormous," said Mauro Martins Teixeira, who heads the immunopharmacology laboratory at the Federal University of Minas Gerais in Brazil. "In an emergency, everyone wants quick answers."

That's why many researchers are taking a closer look at older drugs, testing them to see if they might block infection with the virus or prevent it from harm the brain and nervous system, said Teixeira, who spoke Monday at a Zika conference at Atlanta's Emory University.

Virtually every researcher who works with antiviral drugs is testing them against Zika, Teixeira said.

The ideal drug would not just treat Zika, but also prevent it, much like the antimalarial drugs that travelers take before visiting tropical countries, said Raymond Schinazi, director of Emory's biochemical pharmacology lab. An anti-Zika drug would also have to be safe enough for pregnant women or women of reproductive age.

Schinazi has tested a 40-year-old drug that is safe during pregnancy. The drug has lost its patent, so it could be purchased relatively cheaply, said Schinazi, who has not released the name of the drug.

Teixeira is taking a different approach. Instead of preventing infection, he's looking to protect the brain from Zika's toxic effects. He has tested the Alzheimer's drug memantine, finding that it protects cells in lab dishes and animals. The results, he said, were "astonishing."

Although it's too soon to know if memantine will protect people from Zika's effects, Teixeira hopes to launch a clinical trial to answer that question.

Biotech companies are testing existing drugs, as well.

Atheric Pharmaceuticals, based in Scottsville, Va., has tested about a dozen compounds in lab dishes, said company CEO Robert Malone. Some are antimalarial drugs, while others are natural products and others are drugs that treat infections with parasitic worms.