Evaluation of intravenous to oral antimicrobial switch at a hospital with a tightly regulated antimicrobial stewardship program

Timely intravenous (IV) to oral antimicrobial switch (IV-oral-switch) is a key antimicrobial stewardship (AMS) strategy. We aimed to explore concordance with IV-oral-switch guidelines in the context of a long-standing, tightly regulated AMS program. Data was retrospectively collected for 107 adult general medical and surgical patients in an Australian hospital. Median duration of IV antimicrobial courses before switching to oral therapy was 3 days (interquartile range [IQR] 2.25-5.00). Timely IV-oral-switch occurred in 57% (n = 61) of patients. The median delay to switching was 0 days (IQR 0 to 1.25). In most courses (92/106, 86.8%), the choice of oral alternative after switching was appropriate. In 45% (47/105) of courses, total duration of therapy (IV plus oral) exceeded the recommended duration by >1.0 day. Excessive IV antimicrobial duration was uncommon at a hospital with a tightly regulated AMS program. Total duration of therapy was identified as an AMS target for improvement.