Antimicrobial-associated anaphylaxis at a tertiary care medical city

•The landscape of antimicrobials anaphylaxis is not well described, particularly in an in-patient setting.•We describe the incidence and undesirable outcomes of antimicrobial-associated anaphylaxis at a tertiary care hospital.•Empiric antimicrobial therapy was discontinued in 26% of patients that encountered an antimicrobial anaphylaxis.•Almost half of the patients that encountered an antimicrobial anaphylaxis were switched to a broader spectrum antimicrobial.•Implications of antimicrobial-associated anaphylaxis are beyond the episode itself, and can be associated with poor clinical outcomes. 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 identifiedusing the hospital’s electronic healthcare records. Outcomes included: mortality related to anaphylaxis, infection-related mortality, 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, which required hospitalization in 23.8% of the cases and ICU admission in 19% of the cases. 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 hospitalization.