Effect of Therapeutic Interchange on Medication Changes Between Admission and Discharge

Background: Therapeutic interchange (TI) is the dispensing of an alternative medication within the same class as the original medication. TI often occurs in hospitals; however, failure to return patients to their original medications may increase the risk of adverse effects following hospital discharge. Objective: The purpose of this study was to evaluate the relationship between TI and discharge medication changes, hospital readmission rates, and emergency department visit rates following hospital discharge. Methods: Patient demographic and medication data were collected retrospectively for patients admitted to a nonprofit, acute care hospital. The primary outcome was the relationship between TI and the rate of discharge medication changes. Secondary outcomes included types of discharge medication changes and the relationship between TI and both hospital readmissions and emergency department visits following hospital discharge. Results: A total of 497 patients accounting for 1072 medications were included; 21.2% of home medications were interchanged following admission, and 21.8% of home medications were changed at discharge. TI increased the incidence of discharge medication changes by 70% (odds ratio [OR] = 1.7, 95% confidence interval [CI] = 1.22-2.37, P = .0021). Cardiovascular agents were most likely to be changed at discharge (26%), and gastrointestinal agents were most likely to be interchanged (65%). Psychotropic agents were least likely to be changed at discharge (12%) or interchanged (7%). Neither TI nor discharge medication changes were predictive of 30-, 60-, or 90-day hospital readmission or emergency department visits following discharge. Conclusion and Relevance: This study was the first to examine the effects of TI on post-discharge outcomes. Despite being associated with an increased rate of discharge medication changes, the presence of TI did not correlate with hospital readmission or emergency department visit rates. This study supports the safety of TI.