title: Five-year, multicenter study of a triphasic, low-dose, combination oral contraceptive.
abstract: A total of 4,342 women received a triphasic oral contraceptive combination containing levonorgestrel and ethinyl estradiol (Triphasil in the United States, Trinordiol in Europe) over a 5-year period, for a total of 70,282 cycles. Medication was begun on day 1 in the first cycle, with no backup contraception, and consisted of levonorgestrel (LNg) 50 micrograms + ethinyl estradiol (EE2) 30 micrograms for 6 days, LNg 75 micrograms + EE2 40 micrograms for 5 days, and LNg 125 micrograms + EE2 30 micrograms for 10 days. Twelve pregnancies occurred during the study, resulting in a Pearl Index of 0.22. Medication was missed in an overall total of 5,067 cycles (7.2%), and 9 of the 12 pregnancies were attributed by the investigators to misuse of the drug, resulting in a corrected Pearl Index of 0.06. Cycle control was excellent, bleeding irregularities were minimal, and the incidence of adverse experiences was low (generally less than 1% of total cycles). The results indicate that this triphasic combination, given in pharmacologic doses that are patterned after normal cycles, is a predictable, efficacious, well-tolerated, and accepted means of oral contraception.
authors.affiliation: Hahnemann University, Philadelphia, Pennsylvania.
authors.forename: T B
authors.initials: TB
authors.lastname: Woutersz
authors.forename: V D
authors.initials: VD
authors.lastname: Korba
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002986:Clinical Trials as Topic; D003277:Contraceptives, Oral, Combined; D004997:Ethinyl Estradiol / Q000008:administration & dosage* / Q000009:adverse effects; D019304:Ethinyl Estradiol-Norgestrel Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008597:Menstrual Cycle / Q000187:drug effects; D009644:Norgestrel / Q000008:administration & dosage* / Q000009:adverse effects; D011247:Pregnancy; D006113:United Kingdom; D014481:United States
chemical_list: D003277:Contraceptives, Oral, Combined; D009644:Norgestrel; D004997:Ethinyl Estradiol; D019304:Ethinyl Estradiol-Norgestrel Combination