 In many biologic specimens the levels of fleroxacin are similar to those in plasma, but in bile, nasal secretions, seminal fluid, lung, bronchial mucosa, and ovaries, the drug concentrations are 2-3 times higher than those in plasma.The serum elimination half-life, in subjects with normal renal function, is relatively long (9–12 hours), which permits once-daily dosing.Approximately the urinary excretion is 38% of an orally administered dose within 48 h, and in urine is possible detect 8.6% of the N-demethyl metabolite and 4.4% of the N-oxide metabolite.