title: "Estrophasic" dosing: A new concept in oral contraceptive therapy.
abstract: The first of a new "estrophasic" type of oral contraceptive with 20 microg ethinyl estradiol on cycle days 1 through 5, 30 microg ethinyl estradiol on days 6 through 12, and 35 microg ethinyl estradiol on days 13 through 21 and 1 mg norethindrone acetate throughout the cycle (Estrostep; Parke-Davis, Morris Plains, NJ) combines a continuous low progestin dose with a low, gradually increasing estrogen dose. It was developed to ensure good cycle control while conferring the benefits of low hormone content, such as minimizing estrogen-related side effects. In a double-blind, randomized, parallel-group trial, Estrostep provided acceptable cycle control and excellent tolerableness, comparable to that of the 30-microg ethinyl estradiol monophasic control drug. In a second study Estrostep demonstrated a neutral impact on serum lipids, like the triphasic control drug. This new oral contraceptive design offers a useful low-dose alternative to existing combination preparations.
authors.affiliation: Parke-Davis Pharmaceutical Research Division, Ann Arbor, Michigan, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Rowan
mesh_terms: D000293:Adolescent; D000328:Adult; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage; D003278:Contraceptives, Oral, Hormonal / Q000008:administration & dosage*; D003279:Contraceptives, Oral, Sequential / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004997:Ethinyl Estradiol / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D009640:Norethindrone / Q000008:administration & dosage*