Norethindrone (Norethisterone)
- CAS Codes:68-22-4#51-98-9
- PHARMGKB ID:68-22-4#51-98-9
Table of contents
- Brand Names
- Drug Combinations
- Chemistry
- Pharmacologic Category
- Mechanism of Action
- Therapeutic Use
- Pregnancy and Lactation Implications
- Contraindications
- Warnings and Precautions
- Adverse Reactions
- Caution and personalized dose adjustment in patients with the following genotypes
- Other genes that may be involved
- Substrate of
- Inhibits
- Induces
- Drug Interactions
- Nutrition/Nutraceutical Interactions
- Dosage
- Pharmacokinetics and Pharmacodynamics
Brand Names
Europe
Austria: Micronovum; Belgium: Primolut-Nor; Bulgaria: Primolut-Nor; Cyprus: Primolut-Nor; Czech Republic: Norethisteron; Denmark: Mini-PE; Finland: Mini-Pill, Primolut N; Germany: Gestakadin, Norethisteron, Noristerat, Primolut-Nor; Greece: Norethisterone, Primolut-Nor, Vilcolut; Hungary: Norcolut; Ireland: Noriday, Primolut N; Italy: Primolut Nor; Luxembourg: Primolut-Nor; Malta: Primolut N; Netherlands: Primolut N; Poland: Norethisteron, Primolut Nor; Portugal: Primolut Nor; Slovakia: Norethisteron; Slovenia: Primolut Nor; Spain: Primolut Nor; Sweden: Mini-PE, Primolut-Nor; UK: Micronor, Norethisterone, Noriday, Noristerat, Primolut N, Utovlan.
North America
Canada: Micronor; USA: Aygestin, Camila, Errin, Micronor, Nor-QD, Norethindrone.
Latin America
Argentina: Primolut Nor, Selectan; Brazil: Linatis, Micronor, Norestin, Primolut-Nor; Mexico: Noristerat, Primolut-Nor.
Asia
Japan: Norluten, Primolut N.
Drug combinations
Norethindrone and Estradiol
Norethindrone and Mestranol
Chemistry
Norethindrone: C~20~H~26~O~2~. Mw: 298.42. (1) 19-Norpregn-4-en-20-yn-3-one, 17-hydroxy-, (17α)-; (2) 17-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one. CAS-68-22-4.
Norethindrone Acetate: C~22~H~28~O~3~. Mw: 340.46. (1) 19-Norpregn-4-en-20-yn-3-one, 17-(acetyloxy)-, (17α). CAS-51-98-9.
Pharmacologic Category
Hormones and Synthetic Substitutes; Progestins.
Mechanism of action
Inhibits secretion of pituitary gonadotropin (LH) which prevents follicular maturation and ovulation.
Therapeutic use
Treatment of amenorrhea. Abnormal uterine bleeding. Endometriosis. Prevention of pregnancy.
Pregnancy and lactiation implications
First trimester exposure may cause genital abnormalities, including hypospadias in male infants and mild virilization of external female genitalia. Significant adverse events related to growth and development not observed (limited studies). Use contraindicated during pregnancy. May be started immediately postpartum if not breast-feeding. Enters breast milk (use caution).
Unlabeled use
Contraindications
Hypersensitivity to norethindrone or any component of the formulation. History of or current thrombophlebitis or venous thromboembolic disorders (including DVT, PE). Hepatic dysfunction or tumor. Known or suspected breast carcinoma. Undiagnosed vaginal bleeding. Pregnancy. Missed abortion or as diagnostic test for pregnancy.
Warnings and precautions
Use caution in increased risk of thromboembolism (includes elective surgery associated with an increased risk of thromboembolism or during periods of prolonged immobilization). Use with caution in depression, and in history of migraine. Progestin use associated with retinal vascular lesions. May have adverse effects on glucose tolerance (use caution in women with diabetes), and on lipid metabolism (use caution in women with hyperlipidemias). Irregular menstrual bleeding patterns common with progestin only contraceptives. Use of combination hormonal contraceptives associated with slight increase in frequency of breast cancer, however studies not consistent. Use with caution in diseases which may be exacerbated by fluid retention, including asthma, epilepsy, migraine, cardiac or renal dysfunction. Not for use prior to menarche. Progestin-only contraceptives do not protect against HIV infection or other sexually-transmitted diseases. Risk of cardiovascular side-effects increases in women using estrogen-containing combined hormonal contraceptives and who smoke cigarettes, especially those who are >35 years of age.