Data on safety of intravaginal boric acid use in pregnant and non-pregnant women: a narrative review.

ABSTRACT Intravaginal boric acid (IBA) represents one of the only options available to treat azole resistant vulvo-vaginal candidiasis (VVC), and is included as part of multiple national guidelines (including UK and US) for treatment of VVC or recurrent Bacterial Vaginosis (BV). Novel products utilizing IBA are under development for treatment and suppression of VVC and BV. Use of over the counter (OTC) or clinician-prescribed IBA in reproductive aged women is already widespread, and may increase further if drug resistance in VVC rises. Yet, IBA is not an FDA-approved drug and safety data are sparse. Given these factors, it is important to understand the currently available data on the safety of IBA use. Herein, we set out to synthesize human and animal data (converting, where appropriate, dose and serum values to standard units to facilitate comparison) to answer two key questions: 1. What are the data on the safety of IBA use for women? and 2. What are the data on the safety of IBA use in pregnancy? We find that, despite gaps, available data suggest IBA use is safe, at least when used in doses commonly described in the literature as being prescribed by clinicians. Information on harms in pregnancy is limited and data remain insufficient to change current guidelines which recommend IBA avoidance in pregnancy.