Using a new mathematical approach, scientists have predicted drug side effects that typically aren’t discovered until thousands of people have taken a medication. The technique is especially good at foreseeing side effects that show up after days or months of taking a drug, suggesting that a similar approach could help make drugs safer before they come to market and may even save lives.
Researchers started with a 2005 catalog of existing medications and their known side effects, such as heart attacks or sleeping problems. After linking drugs and their side effects into a network, they instructed a computer to predict likely new connections between drugs and side effects. The program was able to predict 42 percent of the drug–side effect relationships that were later found in patients, the researchers report in the Dec. 21 Science Translational Medicine.
“Adverse drug events are very important and understudied,” says Russ Altman, a biomedical informatics specialist at Stanford University who wasn’t involved with the work. Before a drug ever gets to market it undergoes toxicology testing and clinical trials to establish that it is effective but not dangerous. These trials are often extensive enough to prove that the drug works, but not big enough to say anything meaningful about side effects, says Altman. So, many side effects aren’t discovered until after the drug is on the market.
“You routinely find a whole bunch of annoying ones and every now and then there’s a showstopper,” Altman says. Such interactions lead to 770,000 injuries and deaths each year.