Drug-drug interaction warning analysis
Upon analysis of DDI warnings, we identified a variety of drug combinations. It is important to mention, however, that the DDI combinations listed in table A.4 in the supplementary appendix only refer to those that actually triggered and were not filtered. All warnings that triggered were severe and most were overridden, whereas those that were filtered were mostly moderate in nature. The combination of oral amiodarone and IV haloperidol contributed to 13% of all alerts and occurred in only one patient, resulting in QTc prolongation. Another drug combination was IV ondansetron in addition to IV haloperidol, which triggered in two patients and resulted in QTc prolongation 83% of the time. IV ondansetron formed the majority of the remaining DDI warnings in combination with sotalol, methadone, levofloxacin, ciprofloxacin, propofol, promethazine, trazodone, azithromycin, and arsenic trioxide.