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.
PIP: A Phase I type clinical trial was conducted to study the local toxic effects of nonoxynol-9 (N-9) on the vaginal and cervical mucosa of women, to see whether a Phase II trial is needed, since women may use the spermicide frequently to prevent sexually transmitted diseases. 14 women inserted suppositories containing 150 mg N-9 every hour for 4 doses for 14 days. They were checked before the trail and for 2 or 3 weeks, with pelvic exam, smears for trichomonas and monilia, and colposcopy. 5 women inserted placebos to blind the trial. 43$ of the subjects had physical findings including sloughing of the cervical epithelium in 4, cervical erythema in 4, cervical bleeding in 1, vaginal erythema in 3, vaginal sloughing and bleeding in 1, vaginal dryness in 3, dryness in 2 and itching in 2. The cervical sloughing did not cross the transformation zone. 1 woman had edema and bleeding of the cervix resembling severe strawberry cervix. All symptoms resolved in 1 week. No effects were seen on the vulva, perineum or anus. The dose and frequency of use of N-9 in this trail are larger than women would normally be expected to use, but the data do justify a Phase II study.