Metronidazole as a prophylactic agent in wound infection after colon surgery

Metronidazole was the most effective antianaerobic agent tested in an in vitro system that used a high-density inoculum of mixed enteric organisms. A prospective randomized clinical trial assessing metronidazole and neomycin against erythromycin and neomycin as preoperative bowel preparations demonstrated a marked reduction in the anaerobic flora of patients receiving metronidazole. A second trial revealed that intravenous metronidazole administered 1 hour before and at 8 and 16 hours after the operation provided similar protection against wound infection. Our total experience with 181 patients receiving metronidazole either by mouth or intravenously was three wound infections caused by aerobic enteric organisms, as incidence of 1.6%. There was no wound infection owing to anaerobic organisms of gut origin. The residual problem was that of six wound infections resulting from Staphylococcus aureus presumed to be of skin origin.