Clinical significance of potential drug-drug interactions in a pediatric intensive care unit: A single-center retrospective study.

Despite the high prevalence of potential drug-drug interactions in pediatric intensive care units, their clinical relevance and significance are unclear. We assessed the characteristics and risk factors of clinically relevant potential drug-drug interactions to facilitate their efficient monitoring in pediatric intensive care units. This retrospective cohort study reviewed the medical records of 159 patients aged <19 years who were hospitalized in the pediatric intensive care unit at Seoul National University Hospital (Seoul, Korea) for ≥3 days between August 2019 and February 2020. Potential drug-drug interactions were screened using the Micromedex Drug-Reax® system. Clinical relevance of each potential drug-drug interaction was reported with official terminology, magnitude of severity, and causality, and the association with the patient's clinical characteristics was assessed. In total, 115 patients (72.3%) were exposed to 592 potential interactions of 258 drug pairs. In 16 patients (10.1%), 22 clinically relevant potential drug-drug interactions were identified for 19 drug pairs. Approximately 70% of the clinically relevant potential drug-drug interactions had a severity grade of ≥3. Exposure to potential drug-drug interactions was significantly associated with an increase in the number of administrated medications (6-7 medications, p = 0.006; ≥8, p<0.001) and prolonged hospital stays (1-2 weeks, p = 0.035; ≥2, p = 0.049). Moreover, clinically relevant potential drug-drug interactions were significantly associated with ≥8 prescribed drugs (p = 0.019), hospitalization for ≥2 weeks (p = 0.048), and ≥4 complex chronic conditions (p = 0.015). Most potential drug-drug interactions do not cause clinically relevant adverse outcomes in pediatric intensive care units. However, because the reactions that patients experience from clinically relevant potential drug-drug interactions are often very severe, there is a medical need to implement an appropriate monitoring system for potential drug-drug interactions according to the pediatric intensive care unit characteristics.