The DEVA trial: protocol for a randomised controlled trial of dequalinium chloride versus usual care antibiotics for the treatment of bacterial vaginosis

Background Bacterial vaginosis (BV) is the most common cause of vaginal discharge in women of reproductive age, and it is estimated that up to a third of women will experience it at some point in their lives. BV produces an offensive vaginal odour and it is associated with serious sequelae. The most frequently prescribed treatment for BV in the UK is 7-day oral metronidazole but recurrences are common following it. Dequalinium chloride (Fluomizin©) is an anti-infective, antiseptic agent administered as a vaginal tablet. Small studies have shown this to be an effective alternative to antibiotics as a BV treatment. This trial aims to investigate whether dequalinium is as effective as current antibiotic treatments for the treatment of BV 1 month after treatment start. Methods DEVA is a multi-centre, randomised, open-label, parallel group, non-inferiority trial of dequalinium chloride versus usual care antibiotics for the treatment of BV. Recruitment will take place in 15 GUM clinics in the UK with Leeds Sexual Health also managing remote recruitment via the trial website. Women will be randomised 1:1 to receive dequalinium or usual care antibiotics. The primary outcome is to determine if the proportion of women reporting resolution of BV symptoms 4 weeks after treatment (without the need for additional treatment) is not worse in women treated with dequalinium chloride compared to usual care antibiotics. Questionnaire follow-up will take place 4 and 12 weeks after starting treatment, and remotely recruited patients will also provide a week 4 BV vaginal smear. The sample size is 904. Discussion This trial will provide high-quality evidence on the use of dequalinium chloride as a BV treatment, which could result in patients reducing the number of antibiotics they take. Trial registration ISRCTN ISRCTN91800263. Prospectively registered on 20 January 2020.