Duration of use of metronidazole in the treatment of symptomatic bacterial vaginosis

Bacterial vaginosis (BV) is the most common cause of vaginal inflammation worldwide. The regimens currently recommended for the treatment of bacterial vaginosis are not effective enough, resulting in a high rate of relapse of the disease.

The goal of a randomized trial by J.R. Schwebke et al. (USA), was to determine whether a longer use of metronidazole would lead to an increase in the cure rate of patients with the above pathology. During the study, women with symptomatic bacterial vaginosis (modified Amsel criteria) received metronidazole for 7 and 14 days as monotherapy or in combination with azithromycin (days 1 and 3). In addition to evaluating the efficacy of the treatment regimen used, the patient's sexual behavior was taken into account during the treatment period, as well as the results of a microscopic examination of vaginal discharge with Gram stain.

According to the results, on the 7th day after the end of treatment, there were significant differences in the clinical efficacy of the use of metronidazole for 7 days compared to that for 14 days, both as monotherapy and in association with azithromycin (p = 0.0003). At the same time, 21 days after the end of treatment, no significant difference in the efficacy of all the modes studied was detected. Abstinence or "protected" sexual contact, lack of douching and a lower Nugent index with microscopy of vaginal discharge at the start of the study contributed to a favorable outcome.

Thus, the cure rate of patients with bacterial vaginosis was significantly higher when using metronidazole for 14 days compared to that of 7-day treatment, but over time, due to relapse or reinfection, the differences cease to be significant. The addition of azithromycin to metronidazole was not accompanied by an increase in the effectiveness of treatment.