Pharmacokinetics of rufloxacin in healthy volunteers

The plasma and urine kinetics of rufloxacin were assessed in healthy volunteers after single (100, 200, 400 and 800 mg) and multiple (300 mg followed by 150 mg daily, Group 1, and 400 mg followed by 200 mg daily, Group 2) oral doses. The kinetics of a single oral dose of 800 mg was assessed in fasting and non-fasting subjects to assess the influence of food intake on drug absorption. The AUCs were 134, 266 and 375 micrograms.h.ml-1 after 100, 200 and 400 mg, respectively. The AUC after 800 mg p.o. was 715 micrograms.h.ml-1 in fasting subjects and 614 micrograms.h.ml-1 in non-fasting subjects. The parameters of the model and the mean renal clearance values indicated some departure from linearity in rufloxacin kinetics. After multiple doses the plasma drug levels during the 6th treatment day were similar to those after the first dose in Group 1 and were about 30-40% higher after the first dose in Group 2. The half-lives after the last dose were much shorter than those estimated in the single dose studies (33-36 h and 50-80 h, respectively).