Ortho-Novum Pharmacology, Pharmacokinetics, Studies, Metabolism - Norethindrone and Ethinyl Estradiol

Ortho-Novum Pharmacology, Pharmacokinetics, Studies, Metabolism - Norethindrone and Ethinyl Estradiol

CLINICAL PHARMACOLOGY

Combination Oral Contraceptives: Combination oral contraceptives act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increase the difficulty of sperm entry into the uterus) and the endometrium (which may reduce the likelihood of implantation).

Progestin-Only Oral Contraceptives: The primary mechanism through which norethindrone prevents conception is not known, but progestogen-only contraceptives are known to alter the cervical mucus, exert a progestational effect on the endometrium, interfering with implantation, and, in some patients, suppress ovulation.