National Amoxicillin-Clavulanate Formulation Use Pattern: A Survey

Five commercially available amoxicillin-clavulanate (AMC) ratio formulations contribute to ratio selection variability with efficacy and toxicity implications. The objective of this survey was to determine AMC formulation use patterns across the United States.

A multicenter practitioner survey was distributed to multiple listservs (American College of Clinical Pharmacy pediatrics, infectious diseases, ambulatory care, pharmacy administration; American Society of Health-System Pharmacists; Pediatric Pharmacy Association members), and selected pediatric Vizient members in June 2019. Responses were screened for multiples within institutions. Repeated organization responses were identified (n = 37) and excluded if the duplicate matched another response from the same organization exactly (n = 0).

One hundred ninety independent responses were received. Nearly 62% of respondents represented a children's hospital within an acute care hospital; remainder being from stand-alone children's hospitals. Around 55% of respondents indicated prescribers were responsible for choosing the patient-specific formulation for inpatients. Nearly 70% of respondents indicated multiple formulations were available due to clinical need (efficacy, toxicity, measurable volume), whereas over 40% responded that the number of liquid formulations were limited to decrease the potential for error. Variability was demonstrated among institutions using ≥ 2 different formulations for acute otitis media (AOM), sinusitis, lower respiratory tract infection, skin and soft tissue infection, and urinary tract infection (33.6%, 37.3%, 41.5%, 35.8%, and 35.8%, respectively). The 14:1 formulation was the most common, but not exclusive, for AOM, sinusitis, and lower respiratory tract infections with 2.1%, 2.1%, and 2.6% of respondents indicating use of the 2:1 formulation and 10.9%, 15%, and 16.6% of respondents indicating use of the 4:1 formulation.

Significant AMC formulation selection variability exists across the United States.