Vaginal Clindamycin and Oral Metronidazole for Bacterial Vaginosis: A Randomized Trial

Abstract

Although metronidazole is an effective therapy for bacterial vaginosis, it can be associated with unpleasant and potentially harmful side effects. This study investigated an alternative therapy, clindamycin vaginal ovules, to determine its efficacy and safety as compared with oral metronidazole. Three hundred ninety-nine women with bacterial vaginosis were recruited from 23 European sites to participate in a randomized comparison of the two treatments. The number of participants in each group was sufficient to ensure statistical accuracy in measuring outcomes. Of the 233 patients who were available for evaluation, 113 were randomly assigned to receive 100-mg ovules of clindamycin administered intravaginally once daily for 3 consecutive days, and 120 were randomly assigned to receive 500 mg of metronidazole taken orally in 250-mg capsules twice each day for 7 days. Each group also received placebo capsules or ovules in doses matching the active therapy. Each group had a similar number of women who discontinued therapy prematurely. Cure was defined as the absence of amine odor and clue cells in the vaginal fluid. At both the first and second follow-up visit, 68 percent of the patients were cured in the clindamycin ovule group, whereas 67 percent of the oral metronidazole group were reported cured. There was no difference in the cure rate for either treatment according to participating site, success or failure at first or second visit, or patient assessment of cure (78 percent in the clindamycin group and 80 percent in the metronidazole group). Similar numbers of patients had symptoms of vaginitis or cervicitis at the first and/or second follow-up visit. At each follow-up visit, patients were asked to report any health problems that had occurred since the last visit. The total number of problems reported by each group was similar, but the metronidazole treatment group had more problems associated with the treatment itself (16.3 percent in the metronidazole group and 10.3 percent in the clindamycin group). Nausea and altered taste were more common among the women taking metronidazole than in those using clindamycin. Moniliasis was seen equally in each group. Two women taking metronidazole discontinued treatment the day after beginning therapy, one because of nausea and one because of vulvovaginal itching and swelling. Even though subjects were asked to abstain from sexual intercourse during the study period, one woman in the clindamycin group became pregnant. She gave birth to a healthy infant. Obstet Gynecol 2000;96:256–260