Contraceptive effectiveness and safety of five nonoxynol-9 spermicides: a randomized trial.
OBJECTIVE
To estimate and compare the effectiveness and safety of 5 spermicides over 6 and 7 months of use, respectively. The spermicides included 3 gels containing 52.5 mg, 100 mg, and 150 mg of nonoxynol-9 per dose and a film and a suppository, each containing 100 mg of nonoxynol-9 per dose.


METHODS
Women wishing to use only spermicide for contraception for 7 months were randomly assigned to use 1 of the 5 spermicides with emergency contraception backup. Participants were followed up for up to 30 weeks after admission.


RESULTS
Of 1,536 women enrolled, 868 (57%) either relied on the spermicide for 6 months or became pregnant. The probability of pregnancy during 6 months of typical use of the spermicide was 22% (95% confidence limits 16%, 28%) in the 52.5-mg gel group, 16% (10%, 21%) in the 100-mg gel group, 14% (9%, 19%) in the 150-mg gel group, 12% (7%, 17%) in the film group, and 10% (6%, 15%) in the suppository group. The pregnancy risk in the 52.5-mg gel group was significantly different (P <.05) from that in either of the other gel groups. The pregnancy risks in the three 100-mg product groups were not significantly different (P =.35). No significant differences among groups were found in the 7-month probability of specified urogenital conditions.


CONCLUSIONS
The gel with the lowest amount of nonoxynol-9 was less effective than the 2 higher-dose gels. Among 3 products containing 100 mg of nonoxynol-9, formulation did not significantly affect pregnancy risk. All products were safe.


METHODS
I
Family Health International, PO Box 13950, Research Triangle Park, NC 27709, USA. eraymond@fhi.org
Elizabeth G
EG
Raymond
Pai Lien
PL
Chen
Joanne
J
Luoto
D000293:Adolescent; D000328:Adult; D004304:Dosage Forms; D004305:Dose-Response Relationship, Drug; D005260:Female; D005831:Genital Diseases, Female / Q000139:chemically induced; D006801:Humans; D017137:Nonoxynol / Q000008:administration & dosage* / Q000009:adverse effects; D011247:Pregnancy; D011336:Probability; D013089:Spermatocidal Agents / Q000008:administration & dosage* / Q000009:adverse effects; D013488:Suppositories; D016896:Treatment Outcome; D014622:Vaginal Creams, Foams, and Jellies
D004304:Dosage Forms; D013089:Spermatocidal Agents; D013488:Suppositories; D014622:Vaginal Creams, Foams, and Jellies; D017137:Nonoxynol