Abstract
Objective
The study investigated the contraceptive effect of weekly administration of mifepristone.
Subjects and Methods
A double-blind, randomized clinical trial with weekly doses of 25 or 50 mg of mifepristone
was carried out in three centers in China. Women were assigned to either of two groups.
We defined each study cycle as 28 days. All bleeding data were derived from women's
menstrual cards. The outcome measures were contraceptive efficacy, changes of menstrual
pattern and side effects.
Results
Eighty-three women were enrolled and the outcome was known in 76 women: 39 in the
25-mg group and 37 in the 50-mg group. No pregnancy occurred in both groups in 456
women-months of use accumulated. There were no significant differences in mean bleeding
days and no bleeding days between the two groups in the first three study cycles.
In the fourth, fifth and sixth cycles, mean bleeding days in the 50-mg group (0.86,
1.05 and 0.62, respectively) were significantly less than those in the 25-mg group
(3.5, 2.87 and 2.4 respectively); mean no bleeding days in the 50-mg group (26.07,
25.95 and 26.11, respectively) were significantly more than those in the 25-mg group
(22.93, 23.23 and 23.51, respectively), and the percentage of women who had no bleeding
in a 28-day study cycle in the 50-mg group (22.3%, 25% and 21.1%, respectively) was
significantly more than those in the 25-mg group (2.6%, 3.9% and 3.9%, respectively).
Side effects, such as nausea and breast distension, were uncommon and mild.
Conclusion
Once weekly administration with 25-mg mifepristone is a potentially effective method
for regular contraception.
Keywords
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Article info
Publication history
Published online: October 30, 2006
Accepted:
August 31,
2006
Received in revised form:
August 23,
2006
Received:
May 17,
2006
Identification
Copyright
© 2007 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
