PHARMACOKINETICS OF A SINGLE ORAL DOSE OF LOMEFLOXACIN IN HEALTHY ELDERLY VOLUNTEERS

The pharmacokinetics of lomefloxacin 200 and 400mg, administered orally, were examined in 12 healthy elderly (between 65 and 85 years of age) subjects of both sexes. The drug was well tolerated by all subjects at both doses. Mean C(max) following the 200mg dose was 2.40 mg/L and the mean t(max) was 0.96 hours. Plasma half-life averaged 8.54 hours. Following the 400mg dose, the mean C(max) was 4.48 mg/L, the mean t(max) was 1.31 hours, and the mean plasma half-life was 8.75 hours. Mean urinary excretion rates were highest in the 0 to 4-hour interval after administration for both doses. Mean cumulative urinary excretion, as a percentage of dose, was similar for both doses. Plasma clearance averaged 146.9 ml/min and 143 ml/min for the 200 and 400mg doses, respectively. Renal clearances averaged 100.9 and 84.3 ml/min for the 200 and 400mg doses, respectively. These values were compared to data after single and multiple doses in male volunteers aged 18 to 45. The changes in clearance values observed in our study compared with those in younger subjects were not of sufficient magnitude to warrant reduced dosage in elderly individuals whose renal function is considered adequate for their age.