1506. Outcomes of Standardized Neonatal Cephalexin Dosing

BACKGROUND: The optimal dosing of cephalexin in infants ≤90 days old is not well known. Our Antimicrobial Stewardship Program (ASP) standardized cephalexin dosing for inpatients ≥30 days old using available literature and released an antimicrobial dosing guideline in September 2016. Recommended antimicrobial dosing for inpatients <30 days old followed in November 2017. We reviewed the indications, cephalexin dosing, and clinical outcomes of patients before and after the release of our ASP’s cephalexin dosing guidelines. METHODS: Webi Universe was queried for cephalexin orders for inpatients ≤ 90 days old at the Inova Children’s Hospital from January 2016 to November 2018. Manual chart review extracted clinical points of interest and ensured that inclusion criteria were met. For patients <30 days old, the pre-intervention period was January 2016 to October 2017 and the post-intervention period was November 2017 to October 2018. For patients ≥30 days old the pre-intervention period was January 2016 to August 2016 and the post-intervention period was September 2016 to October 2018. Aggregate data from the two pre-intervention and two post-intervention periods were pooled, respectively. RESULTS: 41 patients were identified: 25 in the pre-intervention period and 16 in the post-intervention period. The median age of patients in the pre-intervention period was 16 days compared with 31 days in the post-intervention period (P = 0.02). No patients had acute kidney injury requiring cephalexin renal dosing. Skin and soft-tissue infections (18) and urinary tract infections (10) were the most common infections in both periods. 24% of patients received the recommended cephalexin dose in the pre-intervention period compared with 63% in the post-intervention period (P = 0.02). Logistic regression controlling for pathogens and area of care showed that patient age predicted the use of recommended cephalexin dosing (OR 1.1, 95% CI: 1.01–1.21). There were no deaths or recrudescent infections. CONCLUSION: Our ASP’s interventions improved adherence to standardized cephalexin dosing in inpatients ≤90 days old without any adverse clinical outcomes. Patients ≥30 days old were more likely to receive recommended cephalexin dosing. Opportunities remain to best define the optimal dose of cephalexin in infants ≤90 days old. DISCLOSURES: All authors: No reported disclosures.