Three-years of dalbavancin use at a UK tertiary referral hospital serving a population with high numbers of people who inject drugs.

Background: Dalbavancin's unique properties have led to an increase in its off-licence use in complex infection and in vulnerable populations including people who inject drugs (PWID), but data remain limited. In this retrospective cohort study, we describe the characteristics, treatment rationale and outcomes for all adult inpatients treated with dalbavancin at a UK tertiary hospital.

Results: Fifty-eight inpatients were treated with dalbavancin between 1 January 2018 and 1 January 2021, 98.3% for off-licence diagnoses. Acute bacterial skin and skin structure infection, infective endocarditis and endovascular infections were each diagnosed in 22.4% of patients. Bone and joint infections were diagnosed in 18.9%, discitis in 12.1% and central line-associated bloodstream infections in 5.2%. Sixty-nine percent of patients were bacteraemic; 52.5% Staphylococcus aureus, 5.0% MRSA. Two mild adverse reactions were attributed to dalbavancin. Treatment was successful in 43 (75.4%) patients, and failed in seven (12.3%). Seven (12.3%) were lost to follow-up.Thirty-five patients (60.3%) were PWID, with low median age (41.0 years) and Charlson Comorbidity scores (0). Self-discharge was taken by 17.1% of PWID, and 20.6% were lost to follow-up. At 90 days, three (8.6%) PWID were deceased.

Conclusions: In this first UK cohort, dalbavancin was used off licence and in persons facing barriers to conventional therapies. Where data is available, it was safe and effective. Dalbavancin appears a potentially valuable tool in improving outcomes for PWID.