The objective of the study was to assess the symptoms and signs of gen
ital 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; G
roup 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 signifi
cantly different from that of placebo users. The rate of epithelial di
sruption 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-91/day and 2/day were 2.5 times greater than that of pl
acebo users. The rate of epithelial disruption for women using N-9 4/d
ay was five times greater than that of placebo users. Genital irritati
on was located primarily on the vagina or cervix, and vulvitis was not
a significant problem. Women who infrequently use N-9 products may no
t experience an increase in genital irritation. Women who choose to us
e N-9 frequently may experience an increase in epithelial disruption.