Challenges for Switching Intravenous to Oral Antimicrobials: Physician Inertia as a Barrier in a Brazilian Hospital

The timely switch from intravenous to oral administration is one of the key actions recommended by Antimicrobial Stewardship Programs. This practice offers several benefits, such as minimizing catheter-related adverse events, reducing treatment costs, and shortening hospital stays, without compromising treatment safety or efficacy. Despite this, up to two-thirds of eligible patients remain on intravenous therapy. Recognizing this scenario may help identify opportunities for improvement in clinical practice and support the implementation of standardized protocols. The objective of the study was to evaluate the frequency of prescriptions in which the route of administration was transitioned for ≥ 72 hours and that met the eligibility criteria. This was a cross-sectional study conducted from January 1 to May 31, 2025, in a teaching hospital located in the southern region of Brazil. Inclusion criteria were adult patients (≥ 18 years) hospitalized in critical and non-critical care units who received intravenous antimicrobials and were clinically eligible for conversion to oral therapy, that is, those with a clinical indication for sequential oral therapy according to institutional protocol. All patients receiving prophylactic antibiotic therapy were excluded. During the study period, six cases of antimicrobial route conversion were identified, five of which occurred in non-critical care units. The antimicrobial classes involved were quinolones, penicillins combined with beta-lactamase inhibitors, and macrolides. The findings reveal a low adherence to intravenous-to-oral antimicrobial conversion practices, even among patients hospitalized in non-critical units and receiving antimicrobials with good oral bioavailability. This scenario highlights the urgent need to implement structured strategies within the antimicrobial stewardship program, including tailored clinical protocols, staff training, and audit and feedback processes, to promote safe and effective adoption of conversion practices. Such measures may contribute to the improvement of key hospital indicators, including optimization of institutional resources and patient safety.