Multiple Weekly Dalbavancin Dosing for the Treatment of Native Vertebral Osteomyelitis Caused by Methicillin-Resistant Staphylococcus Aureus: A Case Report.

BACKGROUND Native vertebral osteomyelitis (NVO) is a common form of hematogenous osteomyelitis, with Staphylococcus aureus (S. aureus) being the most commonly isolated organism. Dalbavancin is approved by the US Food and Drug Administration (FDA) for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and has a sufficiently promising pharmacokinetic and pharmacodynamic profile to be considered for the treatment of vertebral osteomyelitis. We describe here what is probably the first reported case of using multiple weekly dalbavancin to treat a complicated methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and vertebral osteomyelitis. CASE REPORT A 58-year-old man with a long history of recurrent MRSA bacteremia, who failed multiple courses of vancomycin and daptomycin, presented with recurrent MRSA bacteremia complicated by diskitis and osteomyelitis of the lumbar vertebrae. The patient was treated with dalbavancin 1000 mg intravenously weekly for two weeks followed by 500 mg weekly for six additional weeks. He improved clinically, his back pain resolved, and C-reactive protein (CRP) decreased to normal. Three months after the last dose of dalbavancin therapy, he underwent angiography for peripheral artery diseases, after which he developed a fever, mild leukocytosis, an elevated CRP, and the repeat blood cultures were positive for MRSA. No apparent adverse events were observed during dalbavancin therapy. CONCLUSIONS In this case, multiple weekly dalbavancin infusions appeared to be safe in the treatment of vertebral osteomyelitis caused by MRSA, but did not seem to prevent infection recurrence. However, reinfection with a new strain from the angiography catheter insertion is highly likely. Clinical studies are needed to further assess the safety and effectiveness of multiple weekly dalbavancin dosing in the management of vertebral osteomyelitis.