Efficacy and safety of a low-dose monophasic combination oral contraceptive containing 100 microg levonorgestrel and 20 microg ethinyl estradiol (Alesse). North american Levonorgestrel Study Group (NALSG).
The efficacy and safety of a low-dose 21-day combination oral contraceptive containing 100 microg levonorgestrel and 20 microg ethinyl estradiol were evaluated in an open-label, multicenter trial. A total of 1708 subjects with regular menstrual cycles (27,011 cycles) were evaluated. The oral contraceptive was administered once a day for 21 days, followed by 7 days of placebo for a complete cycle. During 26,554 cycles evaluated for efficacy, 18 pregnancies occurred (Pearl index of 0.88); 6 of these events were attributable to subject noncompliance. After 30 cycles of exposure the cumulative rate of withdrawal as a result of accidental pregnancy was 1.9%. Breakthrough bleeding (with or without spotting) occurred in 12.9% of the cycles and spotting alone occurred in 10.1% of the cycles. The 2 most common adverse events cited as reasons for discontinuation were headache (2% of subjects) and metrorrhagia (2%). One serious event led to withdrawal of a subject. Overall, the results of this study demonstrate that the monophasic regimen of 100 microg levonorgestrel and 20 microg ethinyl estradiol offers effective contraception, acceptable cycle control, and a good tolerability profile.
Archer
D F
DF
Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, VA 23507-1627, USA.
Maheux
R
R
DelConte
A
A
O'Brien
F B
FB
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D002584:Cervix Uteri / Q000166:cytology; D003271:Contraceptive Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D045166:Estradiol Congeners / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D006801:Humans; D016912:Levonorgestrel / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D015993:Life Tables; D008597:Menstrual Cycle / Q000187:drug effects; D008875:Middle Aged; D012449:Safety; D016896:Treatment Outcome
D003271:Contraceptive Agents, Female; D003280:Contraceptives, Oral, Synthetic; D004338:Drug Combinations; D045166:Estradiol Congeners; D004997:Ethinyl Estradiol; D016912:Levonorgestrel