Tinidazole prophylaxis in elective colorectal surgery.

Bowel wall concentrations of tinidazole in two patient groups undergoing elective colorectal surgery were determined 8 h (22 patients) and 12 h (26 patients) after a single 500-mg intravenous infusion. In addition, the efficacy of 1-day tinidazole prophylaxis with 8- and 12-h dosage intervals in the prevention of postoperative infection complications was evaluated. The mean bowel wall tinidazole concentrations 8 and 12 h after infusion were 5.1 +/- 2.5 micrograms/g and 4.3 +/- 1.8 micrograms/g, respectively, which are considerably higher than the minimal inhibitory concentration for Bacteroides fragilis strains. Three patients out of 48 (6.3%) developed a wound infection: 1 from the 8-h dosage interval group (4.5%) and 2 from the 12-h interval group (7.7%). Wound cultures revealed only aerobic growth. The results confirm that an adequate bowel wall concentration remains for more than 12 h after a single 500-mg intravenous infusion of tinidazole. One-day tinidazole prophylaxis is an effective means of preventing postoperative infections after colorectal surgery.