Off-Label Use of Dalbavancin in Enterococcus spp. Abscess and Streptococcus pneumoniae Bacteremia Secondary to Septic Arthritis: A Retrospective Case Report

Dalbavancin, a semi-synthetic lipoglycopeptide with an extended half-life that allows for weekly dosing, is currently approved for the treatment of bacterial skin and soft tissue infections caused by susceptible gram-positive organisms. This case report discusses the successful treatment of septic arthritis with dalbavancin in a 38-year-old obese male. Septic arthritis, commonly caused by Staphylococcus aureus and Streptococcus species, was diagnosed in this patient following a mechanical fall that led to worsening shoulder pain. Given the patient's morbid obesity and concerns about antibiotic penetration, dalbavancin 1500 mg IV biweekly was chosen for its extended half-life and ease of administration. This case underscores dalbavancin's efficacy in managing septic arthritis in obese patients, offering a convenient alternative to traditional therapies that require a peripherally inserted central catheter (PICC line), frequent dosing, therapeutic monitoring, and prolonged hospital stays. Despite its higher cost, dalbavancin's advantages include reduced need for PICC lines, additional staff and resources to monitor therapeutic drug levels, and fewer complications, which can offset some expenses. To our knowledge, this is the first documented case investigating the use of dalbavancin for enterococcal septic arthritis with a biweekly dosing regimen.