5PSQ-055 Efficacy and safety of dalbavancin in gram-positive infections treatment

Background and Importance Dalbavancin is a semi-synthetic lipoglycopeptide with activity against gram-positives, including methicillin-resistant Staphylococcus aureus, indicated for skin and soft tissue infections. Unlike other glycopeptides, it has an extremely long half-life, allowing for weekly or biweekly dosing. Aim and Objectives The aim of the study was to evaluate the effectiveness and safety of dalbavancin in gram-positive infection treatment in patients at a tertiary-level hospital. Material and Methods Retrospective, single-centre study. Patients receiving dalbavancin from September 2021 to August 2023 were included. Clinical and analytical data were obtained from medical records. Variables collected: gender, age, antibiotic allergies, type of infection, causative microorganism, previous antibiotic therapy. Regarding treatment: dosage, duration, diagnosis, concomitant antibiotics, clinical and microbiological resolution, adverse reactions (ARs) and discontinuation due to them. Clinical resolution was defined as absence of infection signs, and microbiological resolution as obtaining a negative culture. Results 35 patients were included, with mean age (±SD) of 70 (±11.54) years, 60.7%male. Only one had antibiotic allergy (amoxicillin-clavulanate). All patients had received prior antibiotic treatment before dalbavancin, except one, average duration (±SD) of 20 (±8.5) days. Dalbavancin was prescribed as targeted treatment except for two empiric cases. The indications were: endocarditis 60.0%; prosthetic infection 20.0%; pacemaker infection 8.6%; and the remaining 11.4% included osteomyelitis, septic pseudoarthritis, mycotic aneurysm, and mediastinitis (1 each). Causative microorganisms Staphylococcus epidermidis 28.6%, Viridans-group Streptococcus 20.0%, Methicillin-sensitive S.aureus 14.3%, Enterococcus spp.11.4% (3 E.faecium and 1 E.faecalis), Clostridium spp.11.4%, Methicillin-resistant S.aureus 5.7%, Abiotrophia spp.2.9%. Dosage regimen 48.6% (17) weekly regimen (initial dose 1000 mg, maintenance 500 mg); 34.3% (12) biweekly treatment (initial dose 1500 mg, maintenance 1000 mg); and 17.1% (6) single dose of 1500 mg. Mean duration (±SD) was 4.32 (±3.38) weeks. One patient received concomitant antibiotic treatment due to a polymicrobial infection. Reasons for using dalbavancin was to facilitate discharge and avoid prolonged hospital stays in 27/35 patients, three failed to previous antibiotics, and five had ARs to previous antibiotics. Clinical and microbiological remission was achieved in 85.7%. No patient experienced ARs to the drug. Conclusion and Relevance In our experience, dalbavancin is effective and safe in gram-positive infections requiring prolonged treatments, such as endocarditis. Its pharmacokinetic characteristics enable outpatient-type administration that reduces patient's hospital stay, resulting in increased patient safety and quality of life, as well as significant cost savings in hospital expenses. References and/or Acknowledgements Conflict of Interest No conflict of interest.