Antimicrobial-Associated Anaphylaxis Consequences on Infection Related Mortality and Prolonged Hospitalization

Background: Antimicrobial-associated anaphylaxis occurs at different rates and can lead to worsening infection-related outcomes, we sought to describe the incidence and complications of such episodes at a tertiary care hospital. Method: A retrospective cohort study was conducted between January 2016 and December 2019. Cases of antimicrobial-associated anaphylaxis were identified using the hospital’s electronic healthcare records. Outcomes included: mortality related to anaphylaxis, infection-related mortality, prolonged hospitalization and impact on antimicrobial prescribing. Results: The estimated rate of antimicrobial-associated anaphylaxis was 18.6 (95% CI: 11.8 –29.5) cases per 100,000 exposures. Prolonged hospitalization was seen in 52.4% of the cases, and major predictors for prolonged hospitalization were a switch to a more toxic antimicrobial (P 0.029) and switch to a broader spectrum antimicrobial (P 0.033). Conclusion: Implications from antimicrobial-associated anaphylaxis is beyond the episode itself, and can be associated with poor clinical outcomes such as infection-related mortality and prolonged hospitalization.