Bleeding patterns with monophasic and triphasic low-dose ethinyl estradiol combined oral contraceptives.
BACKGROUND
This retrospective analysis evaluated the association of age and weight with cycle control in women using either of two formulations of low-estrogen-dose oral contraceptives.


METHODS
Data for this secondary analysis were derived from a randomized multicenter trial assessing the efficacy and safety of norgestimate (NGM) 180/215/250 mcg/ethinyl estradiol (EE) 25 mcg (n=1506) and norethindrone acetate 1 mg/EE 20 mcg (n=1057). In this retrospective analysis, the incidence of breakthrough bleeding/spotting (BTB/S) was evaluated in women stratified by age (18-24, 25-34 and >34 years) and weight (<or=123, 124-155 and >155 lb).


RESULTS
A lower percentage of women experienced BTB/S with NGM/EE during most cycles, regardless of age or weight, compared with norethindrone acetate/EE. At Cycle 6, the incidences of BTB/S for NGM/EE versus norethindrone acetate/EE were as follows: 18-24 years, 10.9% versus 29.7% (p<.0001); 25-34 years, 10.9% versus 18.6% (p<.001); >34 years, 8.1% versus 19.1% (p<.005); <or=123 lb, 11.0% versus 25.4% (p<.0001); 124-155 lb, 10.0% versus 22.5% (p<.0001); and >155 lb, 10.0% versus 18.3% (p<.01).


CONCLUSIONS
NGM/EE provided better cycle control as defined by BTB/S compared with norethindrone acetate/EE, regardless of subject age or weight for six cycles.
Hampton
R Moss
RM
Texas Tech University School of Medicine, Odessa, TX 79763, USA. moss.hampton@ttuhsc.edu
Zhang
Huabin F
HF
Barnowski
Christopher
C
Wan
George J
GJ
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001835:Body Weight; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D003280:Contraceptives, Oral, Synthetic / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008598:Menstruation / Q000187:drug effects*; D008796:Metrorrhagia / Q000139:chemically induced; D008875:Middle Aged; D009640:Norethindrone / Q000494:pharmacology; D009644:Norgestrel / Q000031:analogs & derivatives / Q000494:pharmacology; D012189:Retrospective Studies; D016896:Treatment Outcome
D003277:Contraceptives, Oral, Combined; D003280:Contraceptives, Oral, Synthetic; D004967:Estrogens; D009644:Norgestrel; D004997:Ethinyl Estradiol; C017576:norgestimate; D009640:Norethindrone