Lactic acid gel versus metronidazole for recurrent bacterial vaginosis in women aged 16 years and over: the VITA RCT.

Bacterial vaginosis is a common cause of unpleasant vaginal discharge that is caused by an imbalance of vaginal bacteria. The usual treatment is an antibiotic called metronidazole (Flagyl, Sanofi). Although this generally works in the short term, symptoms often return, leading to the repeated use of antibiotics; this can cause side effects as well as increase the risk of antibiotic resistance. Lactic acid gel might be an alternative treatment, but previous studies have not confirmed how clinically effective it is. We wanted to find out if lactic acid gel was better than metronidazole for treating recurrent bacterial vaginosis. Women with typical symptoms and a history of bacterial vaginosis who were taking part in our trial were selected randomly to receive either 7 days of treatment with lactic acid gel inserted into the vagina once per day or 7 days of treatment with metronidazole tablets taken by mouth twice per day. Overall, 518 women took part in the trial. We originally intended to recruit 1900 women but the trial was stopped early because a planned review of the data showed which treatment was better. Most of the women took all of their treatment and 70% reported that symptoms had cleared 2 weeks after taking metronidazole, compared with 47% after using lactic acid gel. Less than half of the women stayed in the trial for the full 6 months; however, the data suggested that the majority of those whose symptoms cleared within 2 weeks with either treatment had symptoms return over the next 6 months. More side effects were reported for metronidazole than for lactic acid gel: nausea 32% compared with 8%, taste changes 18% compared with 1%, and diarrhoea 20% compared with 6%, respectively. Despite thinking that it was less effective, women preferred lactic acid gel because it avoided the need to take an antibiotic and had a soothing effect. The cost-effectiveness analysis found that lactic acid gel was less effective than metronidazole in clearing symptoms by 2 weeks and that the average costs for women whose symptoms resolved were higher (£86.94 with metronidazole vs. £147.00 with lactic acid gel).