1132. Evaluating an Amoxicillin Dosing Regimen for Community Acquired Pneumonia: A Quality Improvement Initiative Using Clinical and Laboratory Data

Abstract Background Amoxicillin 90 mg/kg/day divided twice daily is recommended for children with mild community acquired pneumonia (CAP). While adequate for fully susceptible Streptococcus pneumoniae isolates, three times daily dosing allows achievement of greater amoxicillin exposure, which may be necessary for isolates with penicillin minimum inhibitory concentrations (MIC) of ≥ 2 μg/mL. We evaluated our current twice daily amoxicillin dosing strategy by characterizing 1) the MIC distribution among S. pneumoniae isolates and 2) the frequency of clinical amoxicillin treatment failures. Methods We performed a retrospective cohort study of all S. pneumoniae isolates from sterile and non-sterile sites between 2017-2020. Breakpoints established by the CLSI were used for both meningitis and non-meningitis isolates. Only the first isolate per patient was included. We also evaluated the frequency of amoxicillin treatment failure in patients diagnosed with CAP who were discharged from the ED in 2019. CAP was defined as a discharge diagnosis code for pneumonia and an antibiotic prescription. Treatment failure was defined as an ED or primary care revisit, or admission, within 14 days during which an antibiotic change was made. Results 28 S. pneumoniae isolates were identified from sterile sites between 2017-2020 and 171 isolates were identified overall. All isolates from sterile sites had penicillin MICs of ≤ 2 μg/mL and 165 (96%) of isolates overall had penicillin MICs of ≤ 2 μg/mL (Table 1). Of these, 10 isolates had MICs of 2 μg/mL, all from non-sterile sites. In 2019, 589 patients were treated for CAP in the ED; 447 (76%) received amoxicillin and 142 (24%) were treated with alternative antibiotics. Treatment failures occurred in 15 amoxicillin-treated patients (3.3%, 95% confidence interval 1.9-5.5%) and in 5 patients (3.5%, 95% confidence interval 1.2-8.0%) treated with alternative antibiotics. Conclusion In vitro penicillin resistance was rare at our institution. Further, given that S. pneumoniae is rarely identified by culture, we also demonstrated that clinical amoxicillin treatment failures were infrequent using twice daily amoxicillin dosing. Coupled with provider and family preference, these data supported continuing our current practice of twice daily amoxicillin dosing. Disclosures All Authors: No reported disclosures

. Compliance with antibiotic time-outs over time, by week. The green line represents the goal of 80%, and the orange line represents median performance.  Conclusion. This project demonstrates that ABTOs can be implemented across a variety of teams and showed successful spread of an adult-based QI project to pediatrics. ABTOs led to clear de-escalation in 10.5% of cases, with other changes made in 5% of cases. Future directions include continued spread to inpatient teams, development of EMR-based ABTO alerts, comparison of overall antibiotic use and adverse events before and after ABTO implementation, and characterization of antimicrobial optimization prior to ABTO.
Disclosures. Background. Amoxicillin 90 mg/kg/day divided twice daily is recommended for children with mild community acquired pneumonia (CAP). While adequate for fully susceptible Streptococcus pneumoniae isolates, three times daily dosing allows achievement of greater amoxicillin exposure, which may be necessary for isolates with penicillin minimum inhibitory concentrations (MIC) of ≥ 2 μg/mL. We evaluated our current twice daily amoxicillin dosing strategy by characterizing 1) the MIC distribution among S. pneumoniae isolates and 2) the frequency of clinical amoxicillin treatment failures.
Methods. We performed a retrospective cohort study of all S. pneumoniae isolates from sterile and non-sterile sites between 2017-2020. Breakpoints established by the CLSI were used for both meningitis and non-meningitis isolates. Only the first isolate per patient was included. We also evaluated the frequency of amoxicillin treatment failure in patients diagnosed with CAP who were discharged from the ED in 2019. CAP was defined as a discharge diagnosis code for pneumonia and an antibiotic prescription. Treatment failure was defined as an ED or primary care revisit, or admission, within 14 days during which an antibiotic change was made.

Conclusion.
In vitro penicillin resistance was rare at our institution. Further, given that S. pneumoniae is rarely identified by culture, we also demonstrated that clinical amoxicillin treatment failures were infrequent using twice daily amoxicillin dosing. Coupled with provider and family preference, these data supported continuing our current practice of twice daily amoxicillin dosing. Background. In children, urinary tract infection (UTI) represents one of the most common indications for antibiotics. While previous data has demonstrated high rates of misdiagnosis and inconsistencies with empiric antibiotics, the impact and opportunities for antibiotic reduction once final culture and susceptibility data are available, particularly in pediatric patients seen in the emergency department (ED), is unknown.

Opportunities for Antibiotic Discontinuation and De-escalation after Discharge from the Emergency Department in Pediatric Patients with UTI
Methods. This was a retrospective study conducted over a period of 18-months, which included subjects less than 18 years of age who were discharged from the ED with a diagnosis of UTI. Episodes in which urine cultures were negative or grew only mixed urogenital flora were considered possible for discontinuation. De-escalation was considered possible in episodes in which identified bacteria were susceptible to more narrow spectrum agents than the prescribed empiric antibiotic. Rates of discontinuation and de-escalation were calculated as proportions, and excess days of therapy were described. Subjects whose empiric antibiotics were active against isolated bacteria were compared to those with bacteria resistant to empiric therapy.
Results. A total of 87 episodes of UTI were identified. Pathogenic bacteria were isolated in 51 (59%) of the 78 episodes in which urine cultures were sent, most commonly Escherichia coli (84%). Empiric antibiotic therapy and duration varied and were active against isolated bacteria in 39 (76%) of the episodes. Subjects whose antibiotics were inactive were more likely to be Hispanic and receive cephalexin [ Table 3]. Antibiotics were discontinued in 3 of the 27 possible episodes (11%), resulting in 127 extra antibiotic days, median of 6 (IQR=10 days) days per episode. In 20 episodes there was an opportunity for de-escalation, but it was never attempted, leading to 131 extra days of broad-spectrum antibiotics (median 7.5 days, IQR=3).