Abstract
A randomized, open-label, multicenter study was undertaken to compare the effects
of oral contraceptives (OC) containing 100 μg levonorgestrel (LNG)/20 μg ethinyl estradiol
(EE) (Aless®/Loette®) and 1000 μg norethindrone acetate (NETA)/20 μg EE (Loestrin
Fe 1/20®) on menstrual cycle control over four cycles of use. A total of 84 evaluable
women provided 274 cycles of exposure in the LNG/EE group, and 89 women provided 289
cycles of exposure in the NETA/EE group. Overall, the LNG/EE group achieved a consistently
higher percentage of normal menstrual cycles as well as a lower rate of intermenstrual
bleeding and amenorrhea than the NETA/EE group. In cycle 4, 63.8% of cycles were normal
in the LNG/EE group compared with 41.9% in the NETA/EE group (p < 0.005). Of the total
cycles in the NETA/EE group, 10% were amenorrheic, compared with 1.1% in the LNG/EE
group. The occurrence of bleeding and/or spotting was significantly lower in cycles
2 and 3 in the LNG/EE group (41.7% and 34.8%, respectively) compared with the NETA/EE
group (62.3% and 56.3%; p < 0.05). Other cycle variables were generally similar between
groups, as was the incidence of adverse events. These results demonstrate that good
cycle control was achieved with an OC containing 20 μg EE and that 100 μg LNG/20 μg
EE produces better cycle control than 1000 μg NETA/20 μg EE.
Keywords
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Article info
Publication history
Accepted:
February 10,
1999
Received in revised form:
February 10,
1999
Received:
January 8,
1999
Identification
Copyright
© 1999 Elsevier Science Inc. Published by Elsevier Inc. All rights reserved.
