The effects of frequent nonoxynol-9 use on the vaginal and cervical mucosa

The authors conducted a single-dose phase I local toxicity study of the effects of frequent insertion of nonoxynol-9 (N-9) on the lower genital tract to determine whether a phase II dose-ranging study is warranted. Fourteen women used 150 mg of N-9 cumulatively four times a day for 14 days. Epithelial disruption of the cervix and vagina, the main outcome of interest, occurred in 43% (95% CI, 18-71%) of women on this high-frequency use schedule. None of the women experienced symptoms that prompted them to discontinue the study. This preliminary study indicates that a phase II study to examine the local toxicity of different use schedules is needed to provide further safety information about the use of N-9.