High-dose vaginal metronidazole for recurrent bacterial vaginosis--a pilot study

The purpose of this study was to evaluate high-dose intravaginal metronidazole, with or without miconazole, in enhancing cure rates in women with recurrent BV.

A total of 43 women with symptomatic recurrent BV were enrolled in a 4-arm study comparing 500 mg versus 750 mg of metronidazole, with or without miconazole, intravaginally for 7 days. Test of cure by saline wet mount and 10% potassium chloride microscopy, pH, Gram stain for Nugent score, and yeast culture were performed 3 times after treatment: 3 to 7 days, 30 to 35 days, and 60 to 70 days.

Overall cure rate for the entire group was 92.6% at visit 2, 62.1% at visit 3, and 51.4% at visit 4. At visit 2, there was no difference in cure rates among patients who received metronidazole 750 mg ± miconazole daily (90.5%) compared with metronidazole 500 mg ± miconazole daily (85%). At visit 3, there was a significant improvement in cure rates among patients who received metronidazole 750 mg ± miconazole daily (78.9%) compared with metronidazole 500 mg ± miconazole daily (44.4%) (p < .05). At visit 4, a significant difference in clinical cure rates persisted among patients who received metronidazole 750 mg ± miconazole daily (68.4%) compared with of metronidazole 500 mg ± miconazole daily (33.3%; p < .05). Poor responses (Nugent score > 4 or pH > 4.4) at the first visit alter treatment-predicted recurrence. The addition of miconazole did not enhance BV response rates.

Cure rates for BV were high in this refractory cohort and seemed dose dependent.