Double-blind comparison of a single dose and a five-day course of metronidazole in the treatment of trichomoniasis.

Although there have been reports of the results of treating trichomoniasis with metronidazole 2 g in a single dose, no randomised double-blind comparison of this treatment with a multiple-dose regimen has been reported. In such a comparison, 96 women were treated with metronidazole 2 g in a single dose and 96 women with metronidazole 400 mg twice daily for five days. Forty-eight of 52 women followed for 14 days after the single dose were cured, as were 61 of 66 women followed for 14 days after the start of the five-day regimen. These results compare favourably with previous reports. Side effects were trivial, and we recommend the single 2-g dose, for it is effective, economical, and can be given under supervision in the clinic.