A Dosing Study of Nonoxynol-9 and Genital Irritation

Abstract

The objective of the study was to assess the symptoms and signs of genital irritation produced by different frequencies of nonoxynol-9 (N-9) use. Thirty-five women were randomized to each of 5 groups and used a vaginal suppository for 2 weeks. Group 1: N-9 once every other day; Group 2: N-9 once a day; Group 3: N-9 twice a day; Group 4: N-9 4 times a day; and Group 5: placebo 4 times a day. Study women were examined at admission, one week and 2 weeks with a colposcope for erythema and epithelial disruption, and were interviewed about vaginal itching and burning. The rates of reported symptoms for N-9 users were not significantly different from that of placebo users. The rate of epithelial disruption for women using N-9 every other day was essentially the same as that of women using placebo. The rates of epithelial disruption for women using N-9 1/day and 2/day were 2.5 times greater than that of placebo users. The rate of epithelial disruption for women using N-9 4/day was five times greater than that of placebo users. Genital irritation was located primarily on the vagina or cervix, and vulvitis was not a significant problem. Women who infrequently use N-9 products may not experience an increase in genital irritation. Women who choose to use N-9 frequently may experience an increase in epithelial disruption.

Comparative In Vitro Sensitivities of Human Immune Cell Lines, Vaginal and Cervical Epithelial Cell Lines, and Primary Cells to Candidate Microbicides Nonoxynol 9, C31G, and Sodium Dodecyl Sulfate

“…The need for better preclinical screening methods is illustrated by the historical evolution of N-9, which was shown to be an effective virucidal agent in vitro (18, 21) but appears to be ineffective against HIV-1 in vivo (8,27) and detrimental to the user (26,28). Although presently available in vivo models, including the tissue explant systems (1,9,15) and the human tissue xenograft model (16), can be used to factor the impact of the stratified vaginal epithelial structure into studies of microbicide cytotoxicity, these assays may be limited in scale by tissue sample size and availability.…”

Non nucleoside reverse transcriptase inhibitors

“…Stock solutions of NNRTI were prepared in dimethyl sulfoxide (DMSO). Reaction mixtures (total volume, 50 l) contained 50 mM Tris-HCl (pH 7.8; 37°C), 60 mM KCl, 10 mM MgCl 2 , 1 mM dithiothreitol, 5 g of poly(rC)-oligo(dG) [12][13][14][15][16][17][18] per ml, 20 M [ 3 H]dGTP, and various concentrations of NNRTI. Reactions were initiated by the addition of 20 ng of p51/p66 RT.…”

“…These include detergents such as nonoxynol-9 (13,17) that act by disrupting the virus membrane envelope and agents that inhibit virus binding and entry by blocking CD4 receptors and coreceptors, such as dextran sulfate and modified milk proteins (1,11,12). Some envelope-disrupting detergents, particularly nonoxynol-9, can be toxic to the vaginal epithelium, and there are concerns that these agents may in fact increase the risk of HIV transmission, due to local tissue trauma and inflammation.…”

A Brief Sexual Barrier Intervention for Women Living with AIDS: Acceptability, Use, and Ethnicity

“…15 Despite the ready availability of N-9-based spermicides (marketed as a spermicidal contraceptive), little information exists on the acceptability of such products among seropositive women. This may be due, in part, to the circumstances of use of some forms of N-9, which has been associated with vaginal irritation 22 and lesion-based HIV shedding, 23 either of which may increase risk of STD/HIV transmission.…”