Intravenous metronidazole or clindamycin with tobramycin for therapy of pelvic infections.

Anaerobic bacteria are important pathogens in obstetric and gynecologic infections. As metronidazole has excellent in vitro activity against almost all clinically significant anaerobes, the newly available parenteral form of the drug was evaluated in a comparative study with clindamycin. Forty-seven patients with postpartum endomyometritis with or without wound infection, acute or chronic salpingo-oophoritis, tuboovarian abscess, postoperative pelvic cellulitis or wound infection, or other soft-tissue infection were included in the study. Initially 6 patients were treated with metronidazole, usually combined with tobramycin, in an open study. Subsequently, 41 patients were treated on a randomized schedule of either metronidazole or clindamycin, each combined with tobramycin. Anaerobic bacteria were isolated from 86% (37 of 43) of the patients who had positive cultures from sites cultured for aerobes and anaerobes. Anaerobic gram-negative rods and gram-positive cocci were the predominant isolates from infected tissues. Of the patients who received metronidazole, 96% (25 of 26) were considered clinically cured; the remaining patient initially responded but continued to have slight temperature elevations. There were no adverse reactions to this drug. Of the patients who received clindamycin, 100% were considered clinically cured. The excellent therapeutic response to intravenous metronidazole and the predominance of pathogenic anaerobes observed in these infections support its use in the treatment of infections of the female genital tract.