Publication:

Comparison of intravaginal and oral metronidazole in patients with bacterial vaginosis

Background Metronidazole is considered an effective treatment for bacterial vaginosis. Only oral preparations were available until 2014, but an intravaginal gel preparation recently became commercially available in South Korea. In this report, the efficacy and safety of metronidazole intravaginal gel application was compared to that of the conventional oral metronidazole preparation.

Methods Patients who were treated with either intravaginal metronidazole or oral metronidazole after diagnosis of bacterial vaginosis were included in this study. Patient characteristics, mode of treatment, recurrence rate, and complications including gastro-intestinal discomfort and concomitant vulvovaginal candidiasis were analyzed.

Results There were no differences in patient characteristics, except the mean age was older in the intravaginal group. Treatment outcomes were similar in both groups. In the oral metronidazole group, 6.3% of patients reported ongoing symptoms of bacterial vaginosis within one month of treatment and required a refill, while 7.3% of the intravaginal group required a refill. Significantly more patients on oral metronidazole treatment complained about gastro-intestinal discomfort including nausea (13.4%) and diarrhea (9.4%). Patients who took intravaginal metronidazole complained about increased watery vaginal discharge (26.8%). The comparatively high cost of metronidazole intravaginal gel was another factor that could affect patient access to this treatment versus the oral preparation. The incidence of vulvovaginal candidiasis was similar between groups (oral 3.9%, intravaginal 4.9%).

Conclusions Intravaginal metronidazole usage can be considered as an effective alternative treatment for bacterial vaginosis in patients with gastro-intestinal complications. However, the increased incidence of watery vaginal discharge and high cost remain obstacles to widespread use of the intravaginal preparation.