has part drug identifier potential drug-drug interaction A potential drug-drug interaction (PDDI) is an information content entity that specifies the possibility of a drug-drug interaction based on either reasonable extrapolation about drug-drug interaction mechanisms or a data item created by clinical studies, clinical observation or physiological experiment. Mathias Brochhausen data item about biological process observational data item about drug-drug interaction physiological observation from clinical study data item data item from extrapolation object drug information precipitant drug information information content entity