Excretion of ofloxacin into saliva in rats with renal failure

To clarify effects of renal failure on salivary distribution of ofloxacin (OFLX), a quinolone antibiotics, blood, parotid and mandibular saliva were collected from the single-step 5/6th-nephrectomized and sham-operated (control) rats after bolus i. v. administration of OFLX (5 mg/kg). The concentrations of OFLX in these samples were determined by high-performance liquid chromatography. Renal failure induced by the partial nephrectomy significantly elevated plasma levels and cumulative salivary excretion of OFLX when compared to control rats. Total body clearance was significantly decreased by the renal failure, although salivary clearance of the partially nephrectomized rats was about three times larger than that of the control. At the terminal phase, the saliva/plasma concentration ratios of OFLX for parotid and mandibular saliva in control rats was 0.249 +/- 0.180 and 0.136 +/- 0.024, respectively, and there was a significant difference between both salivary glands. The saliva/plasma concentration ratios in the rats with renal failure were significantly greater than those in the control group in both parotid (about 3.2 times) and mandibular (about 2.5 times) saliva. The results of this study suggest that the salivary excretion of OFLX is significantly increased by renal failure and a glandular difference in the salivary excretion of OFLX exists in both rats with normal and impaired renal function.