Background and Importance The use of intravenous anti-infective therapy for non-hospitalised patients is an increasingly common practice that allows prescribers to treat patients with intravenous therapy without lengthening hospital stay.

Aim and Objectives To assess the prescription pattern and days of admission avoided with outpatient intravenous antibiotic therapy (OPAT). Also, to analyse the safety of this practice.

Material and Methods We made a retrospective observational study including patients who received out-of-hospital intravenous anti-infective treatment in a tertiary-level hospital in Madrid between 1 August 2021, to 31 August 2022. We collected from the electronic prescription indication, etiologic agent, prescribing physician as well as days of hospitalisation avoided, understood as total days of hospitalisation avoided by the number of days of intravenous treatment duration. Also, we recalled adverse reactions that occurred during the therapy period.

Sociodemographic, clinical and pharmacological variables were collected from the electronic medical record.

Results We included 85 patients (52.9% women) in the study, with a median age of 75 years (62–86).

Among the most frequently prescribed anti-infectives we found ertapenem (32.6%), dalbavancin (15.3%), amoxicillin/clavulanic acid (9.2%), ceftriaxone (7.1%) and piperaziline/tazobactam (7.1%). The most frequent indications were urinary tract infections (26.5%), skin and soft tissue infections (18.4%) and respiratory infections (14.3%). As for those infections caused by bacteria (64.7%), 44.6% were gram-negative multi-resistant. Fungi accounted for 4% of the causative agents, protozoa for 1% and viruses for 1%.

Infectious diseases department was responsible of 61.2% of the prescriptions. In 68.4% of cases, there was a complete antibiogram at the time of prescription.

The median of hospitalisation days avoided was 7 (19–6). The highest amount of days avoided was 365 days for three patients, treated for visceral leishmaniasis, mycobacteria infection and infection of sanitary material.

Only 1 patient (1%) presented adverse events (renal toxicity due to amphotericin) that did not require hospitalisation, only suspension of treatment.

Conclusion and Relevance OAPAT receivers in our hospital are mostly elderly patients with bacterial infections. Prescribers made prescriptions based on the results of an antibiogram on more than half of the occasions . The out-of-hospital administration of these drugs saves a median of 7 days for patient, being a practice with low appearance of adverse effects during treatment.

Conflict of Interest No conflict of interest.