Effectiveness and tolerability of lactic acid vaginal gel compared to oral metronidazole in the treatment of acute symptomatic bacterial vaginosis: a multicenter, randomized-controlled, head-to-head pilot study.

Background: Bacterial vaginosis (BV) is a prevalent vaginal condition among reproductive-age women, characterized by off-white, thin vaginal discharge with a fishy odor. It increases susceptibility to sexually transmitted diseases (STDs) and pelvic inflammatory disease (PID). BV involves a shift in vaginal microbiota, with reduced lactobacilli and increased anaerobic bacteria. Standard treatment with oral metronidazole has been shown to have a limited long-term efficacy, possibly due to biofilm persistence. Alternative treatments, such as lactic acid vaginal gel, aim to restore vaginal pH and lactobacilli. This pilot study compares the efficacy and tolerability of lactic acid gel to standard oral metronidazole for acute BV treatment in non-pregnant women.

Methods: A total of 32 women with acute BV were recruited and assigned to either the treatment group (n = 16) where they applied a lactic acid vaginal gel for 12 days, or the control group (n = 16) which received 500 mg oral metronidazole twice daily for seven days. A number of objective and subjective parameters including the Amsel score, the Nugent score and a subjective symptom score were recorded at day 0, three weeks, three months, and six months after the study start.

Results: In the short-term, lactic acid vaginal gel showed inferior clinical (Amsel criteria) and microbiological (Nugent score) cure rates compared to metronidazole. However, it performed equally well regarding subjective symptom improvement and BV recurrence prevention after up to six months.

Conclusion: Lactic acid vaginal gel was generally very well tolerated and showed mixed but promising results as a stand-alone treatment for acute BV.

Trial Registration Number: NCT02042287 (22.01.2014).