Abstract
The pharmacokinetics of pazufloxacin mesilate (PZFX mesilate), a newly developed quinolone antimicrobial agent, were investigated in the elderly. The seven patients (71-88 years old) were classified according to creatinine clearance (Ccr) values into three groups: Group I (n=2), Ccr≥60ml/min, Group II (n=2), Ccr 20-60ml/min, and Group El (n=3), Ccr≤20 ml/min. A 300mg dose of pazufloxacin mesilate given to each patient by 30 minute intravenous infusion. The drug concentrations in serum and urine collected from the patients were determined by HPLC. The results were as follows:
1. Cmax in each group was reached when the infusion was completed.
2. The drug concentrations in serum decreased more slowly in patients with serious renal dysfunction than in those with mild or moderate renal dysfunction.
3. T1/2 grew longer in proportion to the severity of the renal dysfunction: Group I, 2.3-2.4 hr; Group II, 4.6-4.7 hr; Group III, 12.1-18.3hr.
4. AUC also increased according to the severity of the renal dysfunction: Group I, 12.3-17.8μg · h/ml; Group II, 38.5-53.7μg · h/ml; Group III, 94.2-148.2μg · h/ml.
5. The urinary recovery rates up to 24 hours of PZFX mesilate decreased in proportion to the severity of the renal dysfunction: the rates in Group I, II, and III were 80.7-92.8%, 60.9-63.6%, and 12.2-28.6%, respectively.
