2025 Southeastern Residency Conference

Title: Evaluation of Electronic Beta-Lactam Allergy Alert Suppression on Carbapenem Prescribing Practices 


Authors: J. Morgan Knight, PharmD, MHIIM; Brandon Hawkins, PharmD, BCIDP, AAHIVP; Erin Anderson, PharmD, BCPS; Skyler Brown, PharmD, BCPS; Brooke Brown, PharmD, BCPS; John R. Yates, PharmD, BCPS; Jason Tuttle, PharmD Candidate; Samantha Walker, PharmD, BCPS 


Objective: The purpose of this study is to determine if the selective suppression of beta-lactam allergy alerts leads to decreased prescribing of carbapenems.


Self Assessment Question: True/False. Selectively alert suppressing allergies based on R1 side chains significantly impacted the volume of carbapenem prescribing


Background: Beta-lactam antibiotics are commonly prescribed in the United States due to their effectiveness and tolerability. Carbapenems are frequently prescribed in the setting of a penicillin allergy due to the low probability of cross-reactivity. Reducing carbapenem prescribing is essential to decrease resistance rates. Clinical decision support assisted alert suppression of beta-lactams with dissimilar side chains may promote increased prescribing of non-carbapenems. 


Methods: This retrospective quasi-experimental study was approved by the institutional review board at a 710-bed academic medical center.  A total of 819 patients were screened between the months of August 2020-October 2024. Patients were assigned to one of two groups: pre- or post-beta-lactam allergy alert suppression implementation. Group 1 included patients pre-alert suppression from August 1st, 2020, to September 25th, 2022. Group 2 included patients post-alert suppression from September 26th, 2022, to October 1st, 2024. Adult patients with a documented beta-lactam allergy who received at least one dose of an antibiotic were included. Exclusion criteria included allergy alerts that were unable to be suppressed due to Cerner coding limitations (e.g., drug classes listed as “penicillins,” or “cephalosporins”) and patients who only received a one-time dose pre-operatively for surgical prophylaxis. The primary outcome is the percentage of patients prescribed any carbapenem for empiric antimicrobial therapy. Secondary outcomes include percentage of patients empirically prescribed a cephalosporin, fluoroquinolone, and aztreonam, and documentation of a new beta-lactam allergy during current admission. A total of 266 patients were required to detect a 15% difference with a power of 90%.


Results: The percentage of patients prescribed any carbapenem in the pre-alert group and post-alert group were 8.04% and 5.17% (p=0.28), respectively. The percentage of patients empirically prescribed a cephalosporin in the pre-alert group versus the post-alert group was 66.7% and 75.9% (p=0.03), fluoroquinolone 4.60% and 6.32% (p=0.78), and aztreonam 6.90% and 4.02% (p=0.24), respectively. Documentation of a new beta-lactam allergy between pre-and post-groups were 2.30% and 2.87%, respectively.


Conclusion: Allergy alert suppression of beta-lactams did not result in a statistically significant difference in prescribing behavior in our study population, but carbapenem prescribing in the post-suppression cohort was numerically lower. To our knowledge, this is a unique approach to investigating allergy alert suppressions based on side chains alone without consideration of reaction type.