Researchers at Duke University Medical Center have created a “on-off” switch for drug delivery.

In a study published in the Advance Online Publication of the journal Nature Biotechnology published Sunday, the researchers say they have found a way to match an anti-coagulant drug with an antidote designed to prevent bleeding.

The method has been demonstrated successfully in animal models, the researchers say. The National Institutes of Health and the American Heart Association helped support the study.

The advance could help pharmaceutical firms develop a matching agent for new drugs under development.

“These findings have the possibility to significantly change how we care for heart patients,” said Bruce Sullenger, vice chairman of research for Duke’s surgery department and senior member of the research team, in a statement.

Sullenger, and co-researcher Chris Rusconi said they performed the research after Duke cardiologists said they needed a reliable blood-thinning agent that could be administered without the side effect of bleeding.

When bleeding occurs, doctors have little recourse except to wait for the drug to be cleared from the body naturally. Patients who have received anticoagulants and who then must undergo emergency surgery can also face life-threatening delays, Sullenger said in a statement.