Prophylactic regimens in colorectal surgery. Comparison between metronidazole used alone or in combination with either ampicillin or doxycycline.

Sixteen hospitals are participating in this study, that started in October 1982 and will be concluded when 456 patients have been admitted. The study includes patients eligible for elective colorectal surgery. Inclusion criteria, surgical techniques, definition of recognizable infection, sampling of specimens for bacteriological investigations, bacteriologic techniques, and evaluation criteria were standardized. Patients were divided into 2 main groups. Patients in Group 1 received either a single intravenous dose of 1500 mg metronidazole or this dose was combined with a single, intravenous dose of 6 g ampicillin. Patients in group 2 received either a single intravenous dose of 1500 mg metronidazole or this dose combined with a single intravenous dose of 400 mg doxycycline. Dosage regimens were allocated randomly. The current results concern 136 patients. Postoperative infections were seen in 6.7% of the patients receiving metronidazole alone, and 2.9% of the patients receiving metronidazole + ampicillin (Group 1). In Group 2, postoperative infection occurred in 17.1% of the patients receiving metronidazole alone, and in 2.7% of those receiving metronidazole + doxycycline.

A single dose tinidazole and doxycycline prophylaxis in elective surgery of colon and rectum. A prospective controlled clinical multicenter study.

Antimicrobial prophylaxis with agents active against aerobic and anaerobic micro-organisms leads to a significant reduction of infectious complications following colorectal surgery. A single dose (1600 mg) of tinidazole (a nitroimidazole derivate) and doxycycline (400 mg) will provide serum and tissue values well above minimum inhibitory concentration (MIC) values for more than 24 hours. To reduce the unwanted side effects and cost of prolonged antimicrobial prophylaxis, a prospective controlled clinical multicenter study comparing the effect of a single dose before operation of tinidazole and doxycycline to five days of prophylaxis before operation in 234 patients undergoing elective colorectal surgery was undertaken. Six patients given a single dose of prophylaxis before operation (n = 118) developed infectious complication (5.1%). Prolongation of prophylaxis before operation for four days after operation (n = 116) did not lead to any further reduction of infectious complications. A single dose of tinidazole and doxycycline before operation is a simple and effective prophylaxis against infectious complications following elective colorectal surgery.

Tinidazole and doxycycline as antimicrobials in elective colorectal surgery. A randomized multicentre trial.

A prospective randomized study on the effect of doxycycline alone, tinidazole alone and the two antimicrobials in two different combinations as prophylactic antimicrobials on elective colorectal surgery is presented (Table II). The number of patients included in the study was 265. Of the four different treatment groups, the one which consisted of a single preoperative dose of tinidazole 2 g and doxycycline 200 mg, seemed to give the most favourable result. In this treatment group (n = 70), wound sepsis was recorded in 7.2% and perineal sepsis in 34.8% of the cases. Only one serious, but non-fatal intra-abdominal complication (1.4%) was observed in this group. The trial did not include a placebo group.