Successful Treatment of Methicillin-Resistant Staphylococcus aureus Vertebral Osteomyelitis With Outpatient Oritavancin Therapy

Abstract

Native vertebral osteomyelitis (NVO) is a difficult to treat infection often caused by hematogenous spread of bacteria to the bone, causing pain and inflammation. The Infectious Diseases Society of America recommends vancomycin intravenously as first-line treatment for NVO involving methicillin-resistant Staphylococcus aureus (MRSA) for 6 weeks. Alternatives include daptomycin and linezolid. Oritavancin (Orbactiv) is a lipoglypoglycopeptide, structurally similar to vancomycin approved by the Food and Drug Administration for the treatment of acute bacterial skin and skin structure infections caused by susceptible bacteria including S. aureus (both methicillin sensitive and resistant), Streptocococcus, and Enterococcus species. The clinical features of oritavancin are favorable for outpatient use given its broad spectrum of activity for gram-positive organisms and ease of administration; however, clinical experience with the medication is lacking. In this case report, we describe a patient presentation and the evidence for use of oritavancin for the treatment of NVO caused by MRSA. To our knowledge, this is the first reported case of oritavancin for NVO caused by MRSA, and further clinical studies to evaluate it for other indications should be considered.

Continued Dosing of Oritavancin for Complicated Gram-Positive Infections

“…To date, no randomized controlled trials have been conducted to assess oritavancin' s efficacy in off-label indications or continued dosing, but several case reports and retrospective cohort analyses show promising outcomes. [8][9][10][11][12][13][14][15][16] In an analysis of data from the Clinical and Historic Registry and Orbactiv Medical Evaluation (CHROME) patient registry, 32 patients received multiple doses of oritavancin for complicated Gram-positive infections with a 93.8% overall clinical success rate, including success rates of 90.9% (10/11) for general bone and joint infections and 87.5% (7/8) for patients diagnosed specifically with osteomyelitis. 8 Patients received between 2 and 10 doses of 1,200 mg IV given every 6 to 14 days.…”

“…Several case reports and a retrospective chart review study specifically show the effectiveness of oritavancin for osteomyelitis caused by MSSA, MRSA, and VRE. [12][13][14][15][16] However, dosing strategies varied widely after the initial 1,200 mg IV loading dose.…”

“…This conclusion is further corroborated by previously presented research demonstrating successful cure of osteomyelitis with continued dosing strategies. [12][13][14][15][16] Many patients receiving multiple doses of oritavancin did not experience AEs or laboratory abnormalities. 13,15 Four of 17 patients (24%) in one retrospective review experienced AEs, including infusion reactions, anemia, and leukopenia; all were reversible on discontinuation of oritavancin, and contributions of other antibiotics in some cases could not be ruled out.…”

An update on Staphylococcus aureus infective endocarditis from the International Society of Antimicrobial Chemotherapy (ISAC)

“…In another case series, 7 of 10 patients with invasive bacterial infections treated with oritavancin were cured although only one of these patients had a MRSA infection [39]. A notable recent report documented success of therapy with oritavancin for a case of refractory MRSA IE [40]. Oritavancin thus may be useful for MRSA IE although more data are needed before it is recommended.…”

Real-World Use of Oritavancin for the Treatment of Osteomyelitis

“…These features make oritavancin a potentially useful option for the treatment osteomyelitis, although the physiological complexity, severity, and recurrence of these infections will likely require more than a single dose. The use of oritavancin in the off-label treatment of osteomyelitis is currently restricted to a series of case reports, which show that multiple doses of oritavancin are safe and effective in the treatment of osteomyelitis caused by VRE, MSSA, and MRSA [39][40][41][42][43][44][45][46]. We present the reported outcomes of multiple-dose oritavancin therapy in patients with osteomyelitis.…”