Evaluating the impact of electronic β-lactam allergy alert suppression on antibiotic prescribing practices

Suppression of unnecessary allergy alerts for β-lactams with dissimilar side chains may reduce prescribing of alternative agents. This study sought to determine whether selective suppression of β-lactam allergy alerts solely by side chain cross-reactivity could safely decrease prescribing of alternative (carbapenem, monobactam, and non-β-lactam) antibiotics.

This retrospective quasi-experimental study was conducted at a 710-bed academic medical center. In total, 819 encounters between August 2020 and October 2024 were screened. Encounters from August 1, 2020, to September 20, 2022, were assigned to the pre-alert suppression group, while the post-alert suppression group included encounters from October 1, 2022, through March 31, 2024. Adults with a documented β-lactam allergy receiving at least one dose of antibiotic were included. Patients were excluded if they had a nonsuppressible class allergy or received a one-time antibiotic dose for surgical prophylaxis. The primary composite outcome was defined as receipt of a carbapenem, monobactam, or non-β-lactam antibiotic for initial therapy. Secondary outcomes included the percentage of patients initially prescribed an alternative antibiotic by agent, receiving an empiric antibiotic with side chains identical or similar to those of their reported β-lactam allergy, with allergy-related pharmacist interventions, and with documentation of a new β-lactam allergy during the current admission. An interrupted time series analysis was performed for the primary composite outcome.

Individual rates of initial carbapenem, fluoroquinolone, and aztreonam prescription were not significantly different between the groups, although composite prescribing of these agents was significantly lower in the post-alert suppression group (25.4% vs 15.0%; P = 0.016). Initial prescribing of alternative agents per quarter did not significantly change in level or trend after implementation of alert suppression. Documentation of new β-lactam allergies was comparable between the groups.

β-lactam allergy alert suppression yielded a significant reduction in initial composite prescribing of alternative agents. These findings, and the comparable rates of new allergies recorded in the postimplementation group, suggest that alert suppression may be safe and clinically meaningful in antibiotic selection.