ABSTRACT
BACKGROUND: Coronavirus Disease-19 (COVID-19) pandemic impacted the use of antibiotics in hospitalized patients. However, most data on antibiotic therapy (AT) were recorded in COVID-19 settings. This study analyzed the appropriateness of AT in the real-world scenario of a COVID-19-free internal medicine ward before, during, and after the pandemic. METHODS: Clinical information of hospitalized patients was collected, and data related to AT prescription were analyzed. The appropriateness of AT was independently assessed by two specialists in internal medicine and infectious disease, combining evidence-based guidelines with a validated tool. RESULTS: Records of 1249 patients were analyzed: AT was prescribed in 229 (55.2 %) patients before, 134 (53.2 %) patients during, and 315 (54.1 %) patients after COVID-19 pandemic. Compared to the pre-pandemic period, there was a decrease in monotherapy with 3rd and 4th generation cephalosporins and fluoroquinolones, and an increase in ß-lactams + ß-lactamase inhibitors and antibiotic combinations. Furthermore, AT was longer and more expensive during the pandemic, with duration and cost remaining higher after its end. The inappropriateness of AT increased during and after COVID-19 pandemic. Compared to the pre-pandemic period, inappropriate AT was longer and more expensive than appropriate AT. The COVID-19 pandemic had a significant impact on changes related to AT type and antibiotic classes. CONCLUSIONS: The COVID-19 pandemic increased the inappropriateness of AT in a COVID-19-free internal medicine ward. Most modifications persist despite the end of pandemic, potentially leading to negative effects on in-hospital antimicrobial resistance. There is an urgent need to re-establish antimicrobial stewardship policies to address the longer-term global threat of antimicrobial resistance.