Objective: 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.
Methods: 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.
Results: 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.
Conclusion: Both tinidazole regimens studied provided effective treatment for bacterial vaginosis.
Clinical trial registration: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00229216
Level of evidence: I.