Janet F, a 25-year-old interior
designer had the scare of her life after a particularly
wild New Year's Eve celebration. She'd left the party
at 3am with a cute boy she'd met there. She woke up at
his place the next morning with a hangover and not much
of a recollection of the past night's events. Janet rushed
to her doctor's office to get an emergency contraceptive
just in case. She was given levonorgestrel but would she
have been better off with another drug? The results of
a randomized study in the December issue of Obstetrics
& Gynecology demonstrates that mifepristone rivals
levonorgestrel as an oral emergency contraceptive.
The research team from the UK studied
2,065 women who had asked for emergency contraception
within five days of unprotected sex. The women randomly
received small doses of either mifepristone or levonorgestrel.
The number of pregnancies that occurred despite the
hormonal boost was recorded, as were adverse effects
and the time of the first menstrual cycle following
contraceptive use.
The percentage of failure (ie pregnancy)
was 1.3% for mifepristone and 2.0% for levonorgestrel.
In other words, while the prevention of expected pregnancies
was effective for both drugs, mifepristone holds a clear
advantage over levonorgestrel (77% versus 64%). The
resumption of the menstrual cycle was significantly
delayed with mifepristone.
NO
QUESTIONS PLEASE
Over 90% of those taking either drug who completed a
questionnaire were satisfied with the treatment; however,
only one-third of the women in each group completed
the questionnaire. When adverse effects did occur, they
tended to be more inconvenient than debilitating. The
authors conclude "a small dose of mifepristone is not
less effective than levonorgestrel for emergency contraception."
Unfortunately, the trial had to
be ended early because the mifepristone tablets being
used were approaching their expiration date. That, combined
with the low questionnaire participation rate, and a
follow-up compliance rate of only 37%, make the findings
very interesting but as yet equivocal.
Mifepristone first appeared on
the scene in the 1980s. The antiprogesterone drug quickly
became infamous as the 'abortion pill.' Despite a firestorm
of disapproval from anti-abortion groups, the drug was
licensed for use in countries around the world; however,
it hasn't hit Canada yet.
Obstetrics & Gynecology
2004; 104:1307-13
|
