Background Bacterial vaginosis (BV) is a polymicrobial infection and the most common cause of vaginal discharge in women during their reproductive years. A randomised, evaluator-blinded, parallel group pivotal study was carried out to assess the efficacy and safety of the local treatment with nifuratel vaginal tablets in comparison with metronidazole vaginal suppositories in premenopausal, non-pregnant women suffering from BV.

Methods A total of 727 adult women in 38 German sites, with BV diagnosed by Amsel and Nugent criteria, were enrolled after providing their written informed consent. Patients received one course of vaginal treatment with metronidazole 100 mg once daily (o.d.) for six days or nifuratel 250 mg o.d. for ten days. The test of cure visit was performed on day 24 ± 3 after the beginning of the treatment. The efficacy was evaluated using the therapeutic cure rate defined as a combined endpoint including Amsel criteria, clinical signs and symptoms and Nugent score evaluated by a blinded central assessor. The non-inferiority of nifuratel compared to metronidazole at the pre-specified margin of Δ-15% was defined as the clinically acceptable difference between the two active treatments.

Results The therapeutic cure rate was achieved in the per protocol data set by the 53.7% of women: 54.5% in the nifuratel group and 52.9% in metronidazole treated patients (p = 0.0002). Concerning Nugent score (0–3), the two treatments had similar responder rates: 66.2% nifuratel vs. 66.8% metronidazole (p = 0.0006), same results were obtained in terms of Amsel criteria normalisation 78.9% nifuratel vs. 78.6% metronidazole (p = 0.0001). Nifuratel was slightly better to metronidazole curing vulvovaginal signs and symptoms: 81.2% vs. 78.6% (p < 0.0001).

Conclusion The study results suggest that nifuratel 250 mg vaginal tablet o.d. for 10 days may be recommended as first-line treatment in BV as well as the golden standard metronidazole since their efficacy is comparable.