Effectiveness of two tinidazole regimens in treatment of bacterial vaginosis: a randomized controlled trial

To assess the effectiveness at 21-30 days after treatment of tinidazole administered orally at 1 g once daily for 5 days and 2 g once daily for 2 days, compared with placebo, in the treatment of bacterial vaginosis, using rigorous U.S. Food and Drug Administration (FDA)-recommended criteria to define cure.

A total of 235 women at 10 U.S. centers participated in this prospective, randomized, double-blinded, placebo-controlled trial. Presence or absence of all five following criteria was required to define diagnosis or cure of bacterial vaginosis: 1) clue cells were at least 20% of squamous cells in microscopic examination of vaginal fluid; 2) positive potassium hydroxide whiff test; 3) a homogeneous, thin, white-gray vaginal discharge; 4) vaginal pH greater than 4.5; and 5) Nugent score greater than or equal to 4 on Gram-stained vaginal fluid. Compliance, tolerability, and safety were assessed using patient diaries and interviews at 8-10 days and 21-30 days after treatment. Cochran-Mantel-Haenszel statistical analysis with Bonferroni adjustment was used to compare outcomes.

Superior efficacy was demonstrated by tinidazole for the 1 g once daily for 5 days regimen (36.8% cured, P<.001, number needed to treat 3.2) and for the 2 g once daily for 2 days regimen (27.4% cured, P<.001, number needed to treat 4.5), when compared with placebo (5.1% cured) in the primary endpoint analysis. Using more traditional criteria for cure, efficacy was greater. Compliance with study therapy and tolerability were comparable in the three treatment groups.

Both tinidazole regimens studied provided effective treatment for bacterial vaginosis.

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00229216

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