Improving the Percent of Correctly Prescribed Inpatient Amoxicillin/Clavulanate Orders at Phoenix Children’s Hospital
Authors: Armstrong Christian L , Ballan Wassim 
Published: January 2025

Abstract

Corresponding Author: Christian L. Armstrong, PharmD. 1919 E. Thomas Rd, Phoenix, AZ 85016 602-933-1794, carmstrong@phoenixchildrens.com
Alternate Corresponding Author: Wassim Ballan, MD. 1919 E. Thomas Rd, Phoenix, AZ 85016, 602-933-3846, wballan@phoenixchildrens.com
No conflicts of interest

Background
Amoxicillin/clavulanate (AC) is a beta-lactam/beta-lactamase inhibitor that is used to treat a wide variety of infectious conditions. Selection of the proper formulary agent and proper dosing frequency depend on the site of the infection, patient’s age, patient’s weight, and ability to take tablets vs suspension. In pediatrics, prescribers must select the appropriate ratio of amoxicillin to clavulanate to balance the wide dosing range of amoxicillin (15 to 90 mg/kg/day) to the clavulanate portion of 5 to 10 mg/kg/day. Incorrect dosing of AC could lead to patient harm in the form of subtherapeutic dosing causing undertreatment of an infection, compared to overdosing that could increase the risk of adverse effects such as diarrhea. Given AC has many factors to consider when dosing, we sought to identify our baseline error rate and design initiatives to increase the correct dosing of AC at our institution.

Methods
A medication use evaluation (MUE) was performed using data from January to June 2022 to assess the dosing of AC at Phoenix Children’s (PC). Primary outcome of interest was the percentage of inpatient AC orders prescribed correctly comparing baseline to intervention periods. Definition of correct AC dosing is included in Figure 1. Secondary outcomes were the rates of most frequent AC dosing errors (Frequency, amoxicillin dose, and clavulanate dose) from baseline to intervention periods.
Phase I interventions from June to November 2022 included the following: Education of fourteen pharmacists on appropriate AC dosing, daily education to point of care pharmacists on the General Pediatrics floors, presentation of MUE findings to the pharmacy department, and email education on AC dosing to the medical residency program.
Phase II interventions were from January to July 2023 that included: Development of AC dosing pathway/guideline (See Figure 1), education of key stakeholders (hospitalists, medical residents, urgent care/emergency department physicians, and pharmacists) on AC dosing pathway, and AC-specific dose range checking alerts developed.
Data was excluded from December 2022 to July 2023 due to a national AC shortage that required alterations to AC prescribing practices.

Results
From baseline to Phase II interventions, we observed a 34.6% increase in the frequency of correct inpatient AC orders from 41.5% to 76.1%, respectively (Figure 2). A decrease in secondary outcomes/dosing errors seen from baseline to the intervention periods, respectively (Figure 3):

Conclusions
The development of an institutional specific AC dosing guideline, development of dose range checking alerts specific to AC formulation, and education to key stakeholders has helped to increase the correct dosing of inpatient AC orders.

Figure 1: Definition of Correct Amoxicillin/Clavulanate Order and Dosing Algorithm

Figure 2: Percent of Correct Amoxicillin/Clavulanate Orders by Month

Figure 3: Frequency of Dosing Errors