Multiple-dose pharmacokinetics and excretion balance of gatifloxacin, a new fluoroquinolone antibiotic, following oral administration to healthy Caucasian volunteers.

The multiple-dose pharmacokinetics and excretion balance of gatifloxacin were evaluated in 42 healthy Caucasian volunteers. Following multiple oral doses of 400 and 600 mg, the pharmacokinetics of gatifloxacin were similar on days 1 and 15, suggesting no therapeutically relevant time-dependent changes in the pharmacokinetics of gatifloxacin at the doses and duration of dosing studied. Gatifloxacin was rapidly absorbed and a favourable elimination half-life of 7-8 h was evaluated. Saliva concentrations were similar to plasma concentrations. The main route of excretion is the urine. After a single dose of 400 mg of gatifloxacin, the recovery in urine was 83% and 5.2% in faeces. Following multiple doses of 400 or 600 mg, the renal excretion was 80 and 77%, respectively. The drug was well tolerated.