A 12-MONTH COMPARATIVE CLINICAL INVESTIGATION OF 2 LOW-DOSE ORAL-CONTRACEPTIVES CONTAINING 20-MU-G ETHINYLESTRADIOL 75-MU-G GESTODENE AND 30-MU-G ETHINYLESTRADIOL 75-MU-G GESTODENE, WITH RESPECT TO EFFICACY, CYCLE CONTROL, AND TOLERANCE
J. Endrikat et al., A 12-MONTH COMPARATIVE CLINICAL INVESTIGATION OF 2 LOW-DOSE ORAL-CONTRACEPTIVES CONTAINING 20-MU-G ETHINYLESTRADIOL 75-MU-G GESTODENE AND 30-MU-G ETHINYLESTRADIOL 75-MU-G GESTODENE, WITH RESPECT TO EFFICACY, CYCLE CONTROL, AND TOLERANCE, Contraception, 55(3), 1997, pp. 131-137
The aim of this study was to compare contraceptive reliability, cycle
control, and tolerance of an oral contraceptive containing 20 mu g eth
inylestradiol (EE2) and 75 mu g gestodene (GSD), with a reference prep
aration containing a similar dose of gestodene but in combination with
30 mu g ethinylestradiol. A higher incidence of intermenstrual bleedi
ng was apparent under the 20 mu g EE2 oral contraceptive. For the 20 m
u g EE2 preparation, 47.4% of all women reported spotting at least onc
e over a period of 12 treatment cycles, whereas this figure was 35.5%
for the 30 mu g EE2 pill (p < 0.05). However, the incidence was within
a range that corresponds to that of other OCs. The cumulative breakth
rough bleeding rates (at least once during the one year of treatment)
of 14.5% (20 mu g EE2) and 11.8% (30 mu g EE2) of women were not signi
ficantly different. In relation to all cycles, the intermenstrual blee
ding rates were remarkably lower, indicating that the majority of the
volunteers experienced such events only in few cycles under treatment:
the spotting rate was 11.5% (20 mu g EE2) and 7.2% (30 mu g EE2) of a
ll cycles, and the breakthrough bleeding rate was 2.6% and 2.6% of all
cycles, respectively. Three pregnancies were recorded during the stud
y (one in the 20 mu g EE2 + 75 mu g GSD group, two in the 30 mu g EE2
+ 75 mu g GSD group). All three could be explained either by intake ir
regularities or by circumstances impairing the contraceptive effect. T
he influence of both treatments on the blood pressure and body weight
proved to be extremely slight. Adverse events in both groups were rare
and differences in the frequency of adverse events were not apparent.
The discontinuation rate due to adverse events, including intermenstr
ual bleeding, was low (9.8% for 20 mu g EE2 + 75 mu g GSD, and 7.2% fo
r 30 mu g EE2 + 75 mu g GSD) and was in the lower range known for othe
r oral contraceptives. Both preparations were well accepted by the vol
unteers. The data obtained demonstrate clinically acceptable cycle con
trol, good tolerance, and a high standard of contraceptive reliability
for both drugs. Prescription of the 20 mu g EE2 preparation could be
the first-line therapy in order to provide the lowest amount of EE2 po
ssible. In case of persistent cycle problems, a switch to the 30 mu g
EE2 drug should be considered. (C) 1997 Elsevier Science Inc.