Treatment of pyogenic (non-tuberculous) spondylodiscitis with tailored high-dose levofloxacin plus rifampicin

The purpose of this study was to assess the clinical efficacy of high-dose levofloxacin plus rifampicin in the empirical treatment of non-tuberculous spondylodiscitis in an epidemiological context of low incidence of staphylococcal fluoroquinolone resistance. All consecutive adult patients with spondylodiscitis (January 2003 to December 2006) were empirically treated with high-dose levofloxacin (500 mg every 12 h normalised to renal function and optimised by means of therapeutic drug monitoring whenever feasible) plus rifampicin 600 mg every 24 h. Trough and peak plasma concentrations were targeted at 1-3 mg/L and 6-9 mg/L, respectively, to maximise the concentration-dependent activity of levofloxacin in bone. Follow-up was performed until 9 months after the end of therapy. Forty-eight patients were included. Eleven patients underwent a surgical approach for spine stabilisation. Among the 29 bacterial isolates, Staphylococcus aureus was the most frequent (65.5%) (all meticillin-susceptible strains). Tailored levofloxacin plasma exposure over time was ensured in most cases. Median treatment duration was 15.1 weeks. Overall response rates were: 77.1% at the intent-to-treat analysis; 84.1% among patients who completed therapy (N=44); and 96.3% among those receiving targeted therapy against documented levofloxacin-susceptible isolates (N=27). No patient had evidence of disease relapse at follow-up. Our findings suggest that high-dose levofloxacin regimens may be highly effective in the treatment of non-tuberculous spondylodiscitis and support its putative role in combination with rifampicin against S. aureus.