The pharmacokinetics of metronidazole and tinidazole in patients with mixed aerobic--anaerobic infections

Fifteen patients with proven or strongly suspected anaerobic or mixed aerobic-anaerobic infections were treated with tinidazole or metronidazole. In those patients the pharmacokinetics of these drugs were determined for intravenous infusion and for oral administration, whenever possible. Anaerobic infection was proved bacteriologically in three out of eight tinidazole treated and in four out of seven metronidazole treated patients. The clinical outcome of the infection was generally satisfactory in both treatment groups. After intravenous infusion the calculated volume of distribution was 52-1 (S.D. 18-6) 1 for tinidazole and 58-7 (S.D. 30-9) 1 for metronidazole. The plasma clearance was 460 (S.D. 15-1) ml/min for tinidazole and 81-3 (S.D. 28-4) ml/min for metro-nidazole. Calculated absorption after oral administration was 100 % for both drugs.