Effect on vaginal pH of a polycarbophil vaginal gel compared with an acidic douche in women with suspected bacterial vaginosis: a randomized, controlled study

Abstract

Background: Vaginal pH is a key factor in maintaining a healthy vaginal ecosystem. An increase in vaginal pH is commonly observed during bacterial vaginosis. Objective: This study was undertaken to compare the effects of polycarbophil, a new bioadhesive polymer in gel form, with those of an acidic vaginal douche on restoration of physiologic vaginal pH in women with a vaginal pH ≥4.5 and suspected bacterial vaginosis. We also assessed the pH-lowering effect of a single application of polycarbophil compared with that of a single application of acidic vaginal douche in an additional group of women. Methods: In this controlled, randomized, investigator-blinded study, women aged between 18 and 60 years with a vaginal pH ≥4.5 and suspected bacterial vaginosis who were attending a gynecologic outpatient clinic for a routine visit were randomly allocated to receive polycarbophil gel 2.5 g or an acidic vaginal douche twice a week for 6 weeks. We determined vaginal pH by means of a pH meter and the presence of a fishy vaginal odor using a potassium hydroxide (whiff) test at baseline and after each treatment. Vaginal pH was measured in the lateral vaginal fornix at baseline and at weeks 3 and 6 by an investigator who was blinded to treatment. In an additional group of women with a baseline vaginal pH >5.0, we assessed the effect of treatment after a single application of polycarbophil or douche on vaginal pH at baseline and at 8, 32, 56, and 80 hours. Results: Of 45 women screened, 30 women, 2 of whom were pregnant, participated. All completed the study. An additional 8 postmenopausal women (mean age 56 ± 5 years) received a single application of polycarbophil (n = 4) or vaginal douche (n = 4). Polycarbophil significantly ( P < 0.001) reduced vaginal pH from 5.4 to 4.7 ± 0.6 at week 3 and 4.6 ± 0.7 at week 6 compared with baseline and with the vaginal douche group (5.4 ± 0.5 at week 3 and 5.3 ± 0.8 at week 6; not statistically significant). At the end of the study, vaginal pH was significantly ( P < 0.04) lower in the polycarbophil group than in the vaginal douche group (4.6 ± 0.7 vs 5.3 ± 0.8, respectively). Physical and microbiologic signs of bacterial vaginosis were also improved in the polycarbophil group. Both treatments were well tolerated, with no adverse events as determined by the primary investigator. The pH-lowering effect of a single application of polycarbophil gel lasted significantly ( P < 0.01) longer than that of vaginal douche, decreasing from 5.5 at baseline to 4.5 after 80 hours. Conclusions: Our findings show that polycarbophil vaginal gel appears to reduce elevated vaginal pH to physiologic levels for 80 hours compared with acidic vaginal douche and to reduce vaginal pH in women with suspected bacterial vaginosis. Such reduction may help prevent the clinical complications associated with an altered vaginal pH. Randomized, controlled, clinical trials are needed to assess the role of polycarbophil vaginal gel in the long-term treatment of acute and recurrent bacterial vaginosis.