1983. Oral Therapy with Rifampin Associated with Minocycline or Moxifloxacin in Vertebral Osteomyelitis due to Gram-Positive Micro-organisms: A Retrospective Study of 64 Cases

IDSA guidelines about vertebral osteomyelitis (VO) recommend parenteral antimicrobial therapy (PAT) as the standard treatment for Gram-positive pathogens (GPP). In this setting, a switch to oral antimicrobial therapy (OAT) with excellent bioavailability could be considered. However, among fluoroquinolones, moxifloxacine is not recommended in staphylococcal VO, and among tetracycline, only doxycycline should be considered with rifampin, for brucelar VO. The aim of our study was to review the efficacy and safety of OAT with rifampin associated with moxifloxacin (Rif-Mox) or minocycline (Rif-Mino) in the treatment of VO due to GPP.

Observational, retrospective study in a Belgian teaching hospital, over 10 years. All charts with a diagnosis of VO were reviewed. Patients with VO who received definite OAT with Rif-Mox or Rif-Mino were included. An episode of VO caused by the same species within 24 months after the initial episode represented a relapse; other situations were considered as recurrences.

Of 655 charts, 75 matched our inclusion criteria. Eleven were rejected: missing data six cases; death before the end of treatment five cases, including one death related to VO. Key data are shown in the figure. Fifty-five and 9 patients received Rif-Mox and Rif-Mino OAT, respectively. The median duration of PAT and OAT were 14 days and 64.5 days, respectively and the global treatment median duration was 89 days. The duration of PAT was essentially driven by the presence of an associated bacteremia or endocarditis, particularly in cases due to Staphylococci. Interestingly, OAT without initial PAT was performed in six cases without failure. The follow-up after end of therapy was ≥2 years. There was no recurrence or relapse in Rif-Mino group. In Rif-Mox group, there was one recurrence occuring 6 months after the end of therapy. Two others recurrences were observed >24 months after the end of therapy and were not notified. No treatment was stopped because of intolerance or significant adverse events.

OAT with Rif-Mox or Rif-Mino was safe, well tolerated and achieved a high level of cure in VO due to GPPs, including cases with spinal hardware infection.

All authors: No reported disclosures.