Comparison of once-daily and twice-daily dosing of 0.75% metronidazole gel in the treatment of bacterial vaginosis

Background and Objectives: Bacterial vaginosis is the most common cause of vaginal symptoms in women and has potential complications. Efforts to improve treatment of this disease process are warranted. Goal of this Study: The goal of this study was to compare the safety and efficacy of once-daily intravaginal administration of 0.75% metronidazole gel for 5 days to the established twice-daily regimen in the treatment of bacterial vaginosis. Study Design: Nonpregnant women with bacterial vaginosis diagnosed by accepted clinical criteria at 14 geographically diverse general gynecology clinics were enrolled in this prospective, randomized, investigator-blind, parallel study. They were treated with either once-daily or twice-daily 0.75% metronidazole gel 5 g intravaginally for 5 days and were reevaluated at 7 to 12 days and 28 to 35 days after completing treatment. Efficacy was determined by clinical criteria. Adverse drug reactions were monitored. Results: Of the 514 evaluable women enrolled, bacterial vaginosis was cured at the first return visit among evaluable patients in 153 of 199 (77%) of those who received the once-daily and in 157 of 196 (80%) of those who received the twice-daily administration. Bacterial vaginosis was cured among evaluable patients at the final visit in 104 of 180 (58%) of those who received once- daily and 109 of 178 (61%) of those who received the twice-daily regimen. Intent-to-treat analysis showed cure at 1 month in 118 of 207 (57%) of those treated once daily and 129 of 209 (62%) of those treated twice daily. Side effects were mild, and none caused treatment discontinuation. Conclusions: Once-daily dosing of 0.75% metronidazole gel 5 g for 5 days yields efficacy, safety, and tolerance equivalent to the currently used twice-daily dosing in the treatment of bacterial vaginosis, adding another competitive choice to the available therapeutic options for this condition.