The need for translational research on drug-drug interactions.

Drug-drug interactions (DDIs) are an important clinical and public health concern. Although DDI screening now occurs during drug development, it is difficult to predict clinical importance based on in vitro experiments. Furthermore, older drugs that were not screened may have interactions that have not yet been identified. In this Commentary, we review the importance of DDIs and argue that a translational research approach is needed to produce clinically actionable information as well as generalizable biological knowledge.