Cumulative drug interaction burden in intensive care patients: association with polypharmacy and clinical outcomes

Objective

Potential drug–drug interactions (pDDIs) are common in intensive care units (ICUs), but whether they independently contribute to adverse clinical outcomes remains unclear because of their close association with polypharmacy. This study evaluated the associations of cumulative pDDI burden and medication burden with clinical outcomes in medical and surgical ICU patients. Materials and Methods: This retrospective cohort study included 270 adult patients admitted to the medical and surgical intensive care units between January and December 2025. Potential drug–drug interactions were identified using the Lexicomp® database, and the cumulative number of unique pDDIs was calculated for each patient throughout the ICU stay. Multivariable logistic and linear regression analyses were performed to examine the associations of medication burden and cumulative unique pDDI burden with in-hospital mortality, hospital length of stay, and ICU length of stay.