Scientific Poster Session III - Original Research

Abstract

Research Question or Hypothesis: The study aims to determine the consistency among DI resources with respect to scope, severity, completeness, and recommendations provided.

Study Design: cross-sectional, quantitative analysis

Methods: Drug-drug interaction pairs were identified based on questions received from the institution’s Paxlovid™ Hotline. DIs with nirmatrelvir/ritonavir were analyzed by two independent reviewers using five resources: Lexicomp Interactions, Micromedex Drug Interactions, Paxlovid™ Prescribing Information (PI), University of Liverpool COVID-19 Drug Interaction Checker (Liverpool), and the Ontario/University of Waterloo COVID-19 Advisory Table (Ontario). Resources were evaluated for presence of an interaction, severity, completeness, and clinical management. Scales used in the evaluation were adapted from previous literature. Data analysis included descriptive statistics and correlation coefficients.

Results: Of the 102 DI pairs identified, there were 30 common to all five resources. Liverpool contained the most DIs (92%) followed by Lexi (63%), Micromedex (62%), PI (41%) and Ontario (38%). Resources were most similar in severity score. Lexicomp severity levels were highly correlated with three resources (r=0.74-0.75) and to a lesser extent with Micromedex (r=0.54). Completeness scores poorly correlated among resources with Lexi scoring the highest (92%) compared to other resources; Liverpool (59%), Micromedex (57%), Ontario (33%) and PI (5%). Recommendations varied among resources (r=0.44-0.77). The most common recommendation for four references was to give nirmatrelvir/ritonavir while either holding, adjusting, or monitoring the other drug. Liverpool mostly recommended continuing nirmatrelvir/ritonavir therapy without modification, possibly due to its inclusion of more minor DIs.

Conclusion: There are considerable inconsistencies among the DI resources. Such variability could have deleterious effects on patient safety. Clinicians should consult multiple resources when evaluating nirmatrelvir/ritonavir DIs.

Presenting Author

Authors