Protection against lipopolysaccharide-induced death by fluoroquinolones

Because fluoroquinolones have an immunomodulatory effect on cytokine production by lipopolysaccharide (LPS)-treated human monocytes, we examined the effect of fluoroquinolones on the survival of mice injected with a lethal dose of LPS. Trovafloxacin (100 mg/kg), ciprofloxacin (250 mg/kg), and tosufloxacin (100 mg/kg) protected 75% (P = 0.0001), 25% (P = 0.002), and 50% (P = 0.002), respectively, of mice against death. The fluoroquinolones significantly reduced serum levels of interleukin-6 and tumor necrosis factor alpha in LPS-treated mice. The protective effects of fluoroquinolones in LPS-induced shock in mice may also occur in humans.