Artificial intelligence helps Stanford researchers predict drug combinations' side effects

IMAGE: Marinka Zitnik and colleagues designed a system to predict billions of potential drug combination side effects. Last month alone, 23 percent of Americans took two or more prescription drugs, according to one CDC estimate, and 39 percent over age 65 take five or more, a number that's increased three-fold in the last several decades. And if that isn't surprising enough, try this one: in many cases, doctors have no idea what side effects might arise from adding another drug to a patient's personal pharmacy. The problem is that with so many drugs currently on the U.S. pharmaceutical market, "it's practically impossible to test a new drug in combination with all other drugs, because just for one drug that would be five thousand new experiments," said Marinka Zitnik, a postdoctoral fellow in computer science. With some new drug combinations, she said, "truly we don't know what will happen."