[Clinical pharmacology and efficacy of levofloxacin in elderly patients].

We studied a newly developed oral quinolone antimicrobial agent, levofloxacin (LVFX, DR-3355), and obtained the following results. 1. Serum and urine levels of LVFX were determined after oral administration of LVFX 100 mg to 11 elderly patients with various degrees of renal function insufficiencies. The patients were classified according to creatinine clearance (Ccr) values into Group I (n = 1, Ccr greater than or equal to 70 ml/min), Group II (n = 4, 40 less than or equal to Ccr less than 70 ml/min), and Group III (n = 6, Ccr less than 40 ml/min). The peak levels of LVFX did not differ greatly among the 3 groups, but in patients with severely impaired renal functions, serum concentrations decreased more slowly than in those with slightly and moderately impaired renal functions, and high serum levels were maintained over a long period. Urinary excretion of LVFX diminished in relation to degrees of renal failure. 2. LVFX was administered to treat 13 elderly patients with respiratory tract infections. Clinical responses were good in all patients with a high efficacy rate of 100%. Laboratory tests revealed eosinophilia in 1 case. The symptom was mild, however, and no severe side effects due to the drug were observed.