Contraceptive efficacy of a novel spermicidal microbicide used with a diaphragm: a randomized controlled trial.
OBJECTIVE
Women need products that protect against both pregnancy and sexually transmitted infections, including human immunodeficiency virus (HIV). The acid buffering gel is a nondetergent spermicide that may provide this dual protection by reinforcing normal vaginal acidity to inactivate both sperm and acid-sensitive sexually transmitted pathogens. The objective of this study was to assess the gel's contraceptive effects, safety, and acceptability.


METHODS
We conducted a multicenter, randomized, double-masked, noninferiority study at 11 centers, comparing 621 women who used an acid buffering gel plus diaphragm with 300 women who used a nonoxynol-9 spermicide plus diaphragm for 6 months. A double-masked study extension followed 234 women for an additional 6 months of use.


RESULTS
The 6-month pregnancy rate per hundred women was 10.1% (95% confidence interval [CI] 7.1-13.1%) for acid buffering gel and 12.3 (95% CI 7.7-16.9) for nonoxynol-9 spermicide users. The difference in rates was -2.2% with a 95% CI -7.7 to 3.3%. Consistent and correct use 6-month pregnancy rates were 4.7% for acid buffering gel and 6.1% for nonoxynol-9 spermicide users, calculated from those cycles where diary entries indicated such use. Adverse events and acceptability were similar between the two groups. Pregnancy probabilities were similar between groups participating in the 12-month study extension.


CONCLUSIONS
An acid buffering gel used with a diaphragm is a safe, acceptable contraceptive with efficacy comparable to that of a common commercial spermicide with diaphragm.


BACKGROUND
ClinicalTrials.gov, www.ClinicalTrials.gov, NCT00065858


METHODS
I.
Barnhart
Kurt T
KT
University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. Kbarnhart@obgyn.upenn.edu
Rosenberg
Michael J
MJ
MacKay
H Trent
HT
Blithe
Diana L
DL
Higgins
Jim
J
Walsh
Terri
T
Wan
Livia
L
Thomas
Michael
M
Creinin
Mitchell D
MD
Westhoff
Carolyn
C
Schlaff
William
W
Archer
David F
DF
Ayers
Charletta
C
Kaunitz
Andrew
A
Das
Sutapa
S
Moench
Thomas R
TR
D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D003274:Contraceptive Devices, Female / Q000592:standards*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017137:Nonoxynol / Q000008:administration & dosage; D017060:Patient Satisfaction; D011247:Pregnancy; D018873:Pregnancy Rate; D012449:Safety; D012749:Sexually Transmitted Diseases / Q000517:prevention & control*; D013089:Spermatocidal Agents / Q000008:administration & dosage*; D016896:Treatment Outcome; D014622:Vaginal Creams, Foams, and Jellies / Q000008:administration & dosage* / Q000009:adverse effects
D000890:Anti-Infective Agents; D013089:Spermatocidal Agents; D014622:Vaginal Creams, Foams, and Jellies; D017137:Nonoxynol