The effects of three nonoxynol-9 preparations on vaginal flora and epithelium

To evaluate the effects of nonoxynol-9 (N-9) on the vaginal flora and epith elium, 48 women (16 in each group) were evaluated by use of quantitative va ginal. cultures and colposcopy, at baseline and at 0.5, 4, 24, 48, and 72 h after insertion of one of three N-9 preparations (4% gel [Conceptrol], 3.5 % gel [Advantage-24], or a 28% vaginal contraceptive film). The proportion positive for H2O2+ or H2O2- lactobacilli did not change significantly with any of the preparations, but lactobacilli concentrations decreased transien tly. Both the proportion of women with Gardnerella vaginalis and the concen tration of G. vaginalis decreased transiently. The proportion of women with Escherichia coli increased with the 4% gel, and the concentration increase d with all preparations. The number with anaerobic gram-negative rods incre ased, although the concentrations decreased. Symptoms and colposcopic abnor malities were rare. Changes in levels of vaginal bacteria were transient af ter single applications of N-9, but adverse effects may be enhanced with fr equent, chronic use.