AbstractBackgroundΒ-lactam allergy assessment is endorsed by the IDSA as an antimicrobial stewardship tool to enhance the use of first-line agents. We evaluated the impact of pharmacist-driven penicillin (PCN) allergy assessment at the point of prescription on antibiotic use in our emergency department (ED).MethodsRetrospective, quasi-experimental study of adult patients with a PCN allergy receiving antibiotics at a community hospital ED. The intervention comprised an ED pharmacist performing allergy assessment and discussing therapy options with providers at the point of prescription. The primary outcome was to evaluate impact on guideline-preferred antibiotic prescription in the ED pre-intervention (March 1, 2017–August 31, 2017) vs. post-intervention (March 1, 2018–August 31, 2018). Secondary outcomes included types of reported allergic reactions, safety of allergy assessment process, and impact on downstream antibiotic use.ResultsOverall, 381 patients were evaluated (256 pre-intervention, 125 post-intervention). The median age was similar between groups and 85% of patients presented to the ED from the community. Most common infectious syndromes encountered in the ED were UTIs (35%), respiratory tract infections (25%), and skin/soft-tissue infections (18%). The proportion of guideline-preferred antibiotic prescriptions in the ED increased from 37% pre to 44% post (P = 0.171). Proportion of fluoroquinolone (FQ) prescriptions in the ED was reduced from 37.5% pre to 26% post (P = 0.021). Proportion of cephalosporin prescriptions increased from 26% pre to 42% post (P = 0.002). Types of reported allergic reactions were similar between groups and 55% of patients had tolerated a β-lactam agent since the listed allergy. Overall, 70% of patients were hospitalized from the ED. Similar trends in antibiotic use were observed at admission – decreased FQs (38% pre vs. 27% post, P = 0.059), increased cephalosporins (24% pre vs. 38.4% post, P = 0.021). Two patients (1.6%) experienced a nonsevere reaction within 24 hours of β-lactam administration post-allergy assessment.ConclusionPharmacist-driven PCN allergy assessment at the point of prescription in the ED was safe and effective at improving the use of guideline-preferred antibiotics and reducing FQ use.DisclosuresAll authors: No reported disclosures.