Impact of Definitive Drug-Drug Interaction Testing on Medication Management and Patient Care.

Background And Objective: Aegis Sciences Corporation developed a test (InterACT Rx) that objectively and definitively identifies substances known to interact with drug-drug interaction-prone medications commonly prescribed in the treatment of chronic pain and behavioral health disorders. The objective of this study was to assess the severity of identified drug-drug interactions, the reduction in the frequency and severity of identified drug-drug interactions, and the impact of the test on healthcare utilization.

Methods: Patients with chronic pain, behavioral health disorders, or both who had one or more drug-drug interaction tests and one or more drug-drug interactions identified in the study period were included. Drug-drug interaction test results described the number and severity of interactions and detected substances involved in drug-drug interactions. Patients' electronic medical records were obtained to analyze outpatient visits and prescription medications. The cost of outpatient visits was based on the Medicare Physician Fee Schedule. Outcomes were compared between the pre- and post-study index periods to determine the impact of the drug-drug interaction test on patient care.

Results: A total of 262 patients were included. The majority of drug-drug interactions detected (77.9%) at index were of moderate severity. The number of monthly all-cause and pain-related outpatient visits was reduced in the post-index period compared with the pre-index period (0.74-0.54 and 0.69-0.49, respectively). Associated costs were reduced from US$64.92 to US$51.20, and from US$62.42 to US$47.62, (p < 0.0001 for both) for all-cause and pain-related outpatient visits, respectively. Follow-up drug-drug interaction testing for 43 patients revealed that previously reported drug-drug interactions at the index test were no longer identified in the subsequent test for 39.5% of patients.

Conclusions: Employing a definitive test to detect substances whose interactions may cause adverse drug events can enhance a provider's insights, drive clinical decision making, and improve patient outcomes.