Severe Drug-Drug Interactions:Reported and Missed

Abstract

Drug-drug interactions are well known to have major adverse reactions. Many physicians are not aware of all the drugs their patients are taking so these interactions are not known to them. We tested more than 300,000 urine and oral fluid specimens from patients in pain treatment and substance abuse rehabilitation programs for 79 drugs and their metabolites. We used software developed by Elsevier to calculate if there was a severe drug-drug interaction for those specimens which tested positive for two potentially interacting drugs. The severe category was defined as “the use of these medications together is contraindicated, or the medications are not usually taken concurrently because the interaction may be life-threatening or may cause serious harm” We observed 1989 severe interactions. Many were not revealed to the patient’s care giver. We argue such drug-drug interactions are potentially misclassified as “opioid” deaths.