Continuous LNG/EE, a low-dose continuous-use oral
contraceptive, provides similar efficacy and safety to a monthly cyclic oral
contraceptive.
A Teichmann1, C Kluft2, G Grubb3, G Constantine3, D Spielmann4
1Frauenklinik, Klinikum Aschaffenburg, Aschaffenburg, Germany, 2Gaubius
Laboratory, TNO Quality of Life, Biomedical Research, Leiden, Netherlands,
3Research Headquarters, Wyeth Research, Collegeville, PA, United States, 4Wyeth
Research, Paris, France
Objective The efficacy of continuous LNG/EE
(levonorgestrel 90 µg/ethinyl estradiol 20 µg) was assessed and the safety of
this novel low-dose continuous oral contraceptive (OC) was compared to that of a
21-day cyclic OC.
Study Design and Methods Healthy, sexually active women aged
18 to 49 years (N = 641) with a 3-month history of regular menstrual cycles
participated in this phase 3, randomized, 1-year (ie, 13 pill packs), open-label,
multicenter study conducted in Europe to compare the efficacy and safety of
continuous LNG/EE taken daily without a hormone-free interval, with that of a
21-day cyclic OC (LNG 100 µg/ EE 20 µg). Subjects recorded vaginal bleeding on
daily diary cards with bleeding and spotting defined according to WHO standard
definitions.
Results There were no pregnancies among women taking continuous
LNG/EE (n = 323), and 3 pregnancies among those taking the 21-day cyclic OC (n =
318). Over time, a majority of women taking continuous LNG/EE reported
amenorrhea (27.1%, 39.6%, and 52.9% of subjects at pill packs 3, 7 and 13,
respectively). The number of women requiring any sanitary protection during the
pill pack gradually decreased with continuous LNG/EE (49.7%, 31.3%, and 21.0% at
pill packs 3, 7, and 13, respectively). Women in the 2 groups reported a similar
incidence of adverse events (AEs). Bleeding-related AEs (menorrhagia,
metrorrhagia, and vaginal bleeding) were more common with continuous LNG/EE
during pill packs 1 through 6, but were not different between the 2 groups
during pill packs 7 through 13. In contrast, nausea and breast pain were similar
between the 2 groups during pill packs 1 through 6, but were significantly less
common with continuous LNG/EE during pill packs 7 to 13 (P <0.05).
Conclusion
Continuous LNG/EE offers similar safety to that of a 21-day cyclic OC, and
gradually provides amenorrhea or no bleeding for most women.