Effect of sparfloxacin on pharmacokinetics of theophylline in rats

The effect of sparfloxacin on the theophylline pharmacokinetics was investigated in rats.1. The plasma levels and pharmacokinetic parameters of theophylline after a single oral dose (15mg/kg) in rats treated orally with sparfloxacin (100 mg/kg, 3 times) were not significant different from those in control rats, not treated with sparfloxacin.2. After multiple oral administration of theophylline (15mg/kg, twice/day) for 3 days, the maximum plasma concentration of theophylline was 20.2μg/ml in the sparfloxacin-treated rats (100mg/kg, 3 times/day for 3 days) and 21.0μg/ml in the control rats, and there was no effect of the sparfloxacin treatment.3. In the 24-hr urinary excretion of theophylline after a single oral dose (15mg/kg), there was no significant difference between the sparfloxacin-treated (100mg/kg, 3 times) and control rats. Moreover, the sparfloxacin treatment also did not affect the amount of the theophylline metabolites excreted in urine.4. In conclusion, sparfloxacin shows no significant effect on the pharmacokinetics of theophylline in rats.