indication

Norelgestromin is used for contraception and menopausal hormonal therapy. Norelgestromin may potentially be used in breast cancer treatment due to its inhibitory effect on estrone sulfatase . They convert sulfated steroid precursors to estrogen during pregnancy.

pharmacology

Norelgestromin is used for contraception and menopausal hormonal therapy transdermally or in combination with ethinyl estradiol as a vaginal ring. Norelgestromin, in combination with ethinyl estradiol inhibits ovulation by suppressing gonadotropins.

mechanism of action

Norelgestromin inhibits estrone sulfatase, which converts sulfated steroid precursors to estrogen during pregnancy. Norgelgestromin/ethinylestradiol suppresses follicular development, induces changes to the endometrium, which decreases chances of implantation and thickens the cervical mucus, impeding sperm swimming into the uterus. It also has similar agonisting binding affinities as its parent compound, Norgestimate, for progesterone and estrogen receptors.

drug interactions

Artemether: Artemether may decrease the effectiveness of norelgestromin by increasing its metabolism via CYP3A4. Consider an alternate non-hormonal means of contraception during artemether therapy.

Bexarotene: Bexarotene may decrease the serum concentration of Contraceptives (Progestins). Since bexarotene is teratogenic and can lower serum concentrations of norelgestromin, it is advised that women of childbearing potential use two forms of contraception (including at least one non-hormonal form).

Colesevelam: Bile Acid Sequestrants may decrease the serum concentration of Contraceptives (Progestins). Administer oral progestin-containing contraceptives at least 1-4 hours prior to or 4-6 hours after administration of a bile acid sequestrant. Consider alternatives in order to avoid this combination when possible, due to the risk for impaired contraceptive effectiveness.