title: Single-dose intravenous metronidazole v. doxycycline prophylaxis in colorectal surgery. An open prospective, randomized trial.
abstract: In an open prospective, randomized study of antimicrobial prophylaxis in colorectal surgery, using a single intravenous dose, metronidazole (1 g) was more effective than doxycycline (0.2 g). The difference in infection rates (2/41 = 5% v. 7/33 = 21%) was statistically significant. Prolonged administration of either agent (2-7 days) yielded results comparable to those with single doses. Five emergency cases were admitted to the study. In two of them, a metronidazole-based therapeutic regimen prevented postoperative infection, whereas infection occurred in all 3 patients given doxycycline therapy. The total infection rate after elective surgery was 4% with metronidazole and 25% with doxycycline prophylaxis. The infections in the metronidazole group were superficial and caused by Escherichia coli, whereas half of the infections in the doxycycline group were intra-abdominal and due to intestinal aerobic and/or anaerobic bacteria. In contrast to doxycycline, therefore, metronidazole prevented postoperative anaerobic infection and was associated with low incidence of aerobic infection.
mesh_terms: D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D003108:Colonic Diseases / Q000601:surgery*; D004318:Doxycycline / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage*; D008875:Middle Aged; D011446:Prospective Studies; D011897:Random Allocation; D012002:Rectal Diseases / Q000601:surgery*; D013530:Surgical Wound Infection / Q000517:prevention & control*
chemical_list: D008795:Metronidazole; D004318:Doxycycline