Ciprofloxacin treatmentin vivoincreases theex vivocapacity of lipopolysaccharide-stimulated human monocytes to produce IL-1, IL-6 and tumour necrosis factor-alpha

Because in vitro treatment with quinolones, at pharmacological concentrations, modifies lipopolysaccharide (LPS) induced production of cytokines by monocytes, we studied the effect of orally administered ciprofloxacin (25 mg/kg) on the capacity of peripheral blood monocytes of healthy volunteers to produce tumour necrosis factor-alpha (TNF-alpha), IL-1 activity, IL-1 alpha, IL-1 beta and IL-6 ex vivo in response to endotoxin stimulation. After 7 days of ciprofloxacin, the extracellular and cellular production of TNF-alpha, the cellular production of IL-1 activity, the extracellular and cellular production of IL-1 alpha, and the cellular production of IL-6 increased significantly. Seven days after the end of the treatment, values returned to basal levels or even lower. To our knowledge, this is the first demonstration that ciprofloxacin can modulate in vivo the capacity of human monocytes to react to an inflammatory stimulus such as endotoxin.