The Influence of Oral versus Parenteral Preoperative Metronidazole on Sepsis Following Colon Surgery

Abstract

The incidence of wound infection following surgery on the colon is reduced by the preoperative adminstration of appropriate antibiotics. Quantitative bacteriologic studies raise the fundamental question as to whether effective antibiotic prophylaxis results from reduction of the bacterial content of the gut prior to surgery or whether effective tissue levels of the antibiotic is the key factor. Oral neomycin and metronidazole have been shown to markedly reduce the incidence of wound infection following colon surgery. A prospective randomized double-blind clinical trial was undertaken to compare the effectiveness of intravenous metronidazole (high tissue level) with oral administration (tissue and gut activity) on the incidence of wound infection. There was no difference in wound infection rates between the two groups of patients. Surprisingly, there was a significant reduction in the bacteroides content in the colon of patients who received intravenous metronidazole one hour before operation to a level almost equal to that achieved by the administration of the drug for two days by mouth before operation. Metronidazole levels in the colon at the time of surgery were comparable for both groups. The median time for recolonization of the colon was six days for the oral group, and four days for the intravenous group. Although peritoneal fluid contained significant numbers of coliforms and enterococci, clinical infection did not occur. These data suggest that systemic antibiotics effective against anerobic flora of the colon markedly reduce postoperative septic complications.

Effects of oral administration of metronidazole on small intestinal bacteria and nutrients of cats

“…This amount of time was considered more than adequate on the basis of studies in humans, which revealed the bacteroides content of fecal flora was reestablished by 6 days after cessation of orally administered metronidazole. 19 To determine that bacteria had recolonized the duodenum in the cats of our study, samples of duodenal fluid were submitted for bacterial culture. Blood samples also were obtained and analyzed for serum concentrations of total protein, albumin, cobalamin, and folate.…”

Clinical practice guidelines for antimicrobial prophylaxis in surgery

“…The most common combinations include an aminoglycoside (neomycin and, less often, kanamycin, which is only available in injectable form in the United States) plus a medication with anaerobic activity, usually erythromycin [427][428][429][430][431][432][433][434] or metronidazole. 432,433,[435][436][437][438][439] In placebo-controlled studies, the oral combination was significantly more effective than placebo in reducing SSIs. 427,433,434,439,440 Postoperative SSI rates were 0-11% with neomycin plus erythromycin 427-432 and 2-13% with neomycin and metronidazole.…”

“…427,433,434,439,440 Postoperative SSI rates were 0-11% with neomycin plus erythromycin 427-432 and 2-13% with neomycin and metronidazole. [436][437][438] Combinations of neomycin and tetracycline, 440 neomycin and clindamycin, 436 and neomycin and tinidazole 441 have also been used successfully, with postoperative SSI rates of <10%. The use of metronidazole as a single agent appears to be less effective, with reported SSI rates of 12-15%.…”

Antibiotic Prophylaxis in Colorectal Surgery: Evolving Trends

“…A variety of oral agents administered after MBP have been evaluated (Table 4). The most common combinations include an aminoglycoside (neomycin and, less often, kanamycin) plus a medication with activity against anaerobes, usually erythromycin [16,91] or metronidazole [92][93][94].…”