Maternal androgenic symptoms occurred most often in women who received a dosage of norethisterone of 30 mg/day or more for a period of 15 weeks or longer. In the female infants who experienced virilization of the genitals, the sole manifestation in 86.7% of the cases was varied but almost always slight enlargement of the clitoris. In the remaining 13.3% of the affected cases, marked clitoral enlargement and partial fusion of the labioscrotal folds occurred. The dosages used in these cases were 20 to 40 mg/day.In a letter to the editor on the topic of virilization caused by high dosages of NETA in women, a physician expressed that they had not observed the "slightest evidence of virilization" and that there had "certainly been no hirsutism nor any voice changes" in 55 women with advanced breast cancer that they had treated with 30 to 60 mg/day norethisterone for up to six months.High-dosage norethisterone has been used to suppress menstruation in women with severe intellectual disability who were incapable of handling their own menses. A study of 118 nulliparous women treated with 5 mg/day norethisterone for a period of 2 to 30 months found that the drug was effective in producing amenorrhea in 86% of the women, with breakthrough bleeding occurring in the remaining 14%. Side effects including weight gain, hirsutism, acne, headache, nausea, and vomiting all did not appear to increase in incidence and no "disturbing side effects" were noted in any of the women.
In 1964, additional contraceptive preparations containing norethisterone in combination with mestranol or EE, such as Norlestrin and Norinyl, were marketed in the United States. Society and culture
Generic names
Norethisterone is the INN and BAN of the drug while norethindrone is its USAN. Brand names
Norethisterone (NET), including as NETA and NETE, has been marketed under many brand names throughout the world. Availability
United States
Norethisterone was previously available alone in 5 mg tablets under the brand names Norlutin in the United States, but this formulation has since been discontinued in this country. However, NETA remains available alone in 5 mg tablets under the brand name Aygestin in the United States. It is one of the only non-contraceptive progestogen-only drug formulations that remains available in the United States. The others include progesterone, medroxyprogesterone acetate, megestrol acetate, and hydroxyprogesterone caproate, as well as the atypical agent danazol.Both norethisterone and NETA are also available in the United States as contraceptives. Norethisterone is available both alone (brand names Camila, Errin, Heather, Micronor, Nor-QD, others) and in combination with EE (Norinyl, Ortho-Novum, others) or mestranol (Norinyl, Ortho-Novum, others), while NETA is available only in combination with EE (Norlestrin, others). NETE is not available in the United States in any form. Research
Norethisterone, as NETA and NETE, has been studied for use as a potential male hormonal contraceptive in combination with testosterone in men.Long-acting norethisterone microspheres for intramuscular injection have been studied for potential use in birth control. References
Further reading
External links
"Norethindrone". Drug Information Portal. U.S. National Library of Medicine.