Direct Costs of Unnecessary Antibiotic Prescribing in Patients Administered Imipenem in the Emergency Department

Abstract

Specific Aims: The aim of this study was to examine the appropriateness of antibiotic use in the first 48 hours of being admitted to the emergency department in a tertiary care medical center. The purpose was to identify inappropriate usage patterns of antibiotics to limit future misuse and prevent the unintended consequences of overuse of antibiotics. Methods: Patients 18 years and older who were admitted to the emergency department at University of Arizona Medical Center – University Campus who were administered imipenem within 48 hours of admission were included. All antibiotics received by included patient were recorded and assessed for appropriateness by two pharmacists with specialized infectious disease training. Inappropriate use of carbapenems or other antibiotics in conjunction with carbapenems was identified and the acquisition cost of the misused antibiotics was calculated. Main Results: Imipenem use was considered inappropriate in 35/52 (71.1%) of patients included in this study. The direct cost of inappropriate antibiotic prescribing was $914.77. Multiple β-lactam antibiotics were used in 24/52 (46.1%) patients while 18/52 (34.6%) of patients received four or more antibiotics within the first 48 hours of admission. Conclusion: Imipenem was frequently used empirically for in cases did not fit the predetermined criteria of use within 48 hours of admission emergency department of the University of Arizona Medical Center – University Campus, resulting in unnecessary direct costs to the medical center.