From the Guidelines
Norethindrone should be used at a minimum dose of 1 mg daily for continuous regimens in hormone replacement therapy (HRT) for patients with premature ovarian insufficiency (POI), as per the most recent guidelines 1. When considering the use of norethindrone, it's essential to evaluate the specific medical condition being treated. For HRT in patients with POI, the dosage and administration route may vary.
- The recommended dose for continuous regimens is at least 1 mg of oral norethisterone daily 1.
- In cases where combined 17βE and progestin patches are not available, transdermal 17βE can be administered continuously, and oral (or vaginal) progestin can be added cyclically for 12–14 days every 28 days 1.
- Adult doses of oral progestin depend on the doses of estrogen administered, with sequential regimens requiring 200 mg of oral (or vaginal) medroxyprogesterone (MP) for 12–14 days every 28 days, or 10 mg of medroxyprogesterone acetate (MPA) for 12–14 days per month, or 10 mg of dydrogesterone for 12–14 days per month 1. It's crucial to note that among progestins, MP is the first choice due to its association with a lower risk of cardiovascular disease and venous thromboembolism when taken with cyclical administration 1.
- Norethisterone is considered a second-choice option, and its use should be guided by the patient's specific needs and medical history.
- Patients with iatrogenic POI may suffer from diminished libido or impaired sexual function due to low circulating testosterone levels, and progestins with an anti-androgenic effect, such as norethisterone, could worsen hypoandrogenism and should be avoided in this specific cohort of patients 1.
From the FDA Drug Label
To achieve maximum contraceptive effectiveness, norethindrone tablets must be taken exactly as directed. One tablet is taken every day, at the same time. Administration is continuous, with no interruption between pill packs. The proper usage and dosage of norethindrone for contraceptive purposes is to take one tablet every day at the same time, with no interruption between pill packs, as directed to achieve maximum contraceptive effectiveness 2.
- Key points:
- Take one tablet daily
- Take at the same time every day
- Continuous administration with no interruption between pill packs There is no information provided about the dosage for other medical conditions.
From the Research
Norethindrone Usage and Dosage
- Norethindrone is a progestin used to treat various medical conditions, including endometriosis, uterine bleeding, and infertility 3, 4, 5, 6, 7.
- The dosage of norethindrone varies depending on the condition being treated:
- For symptomatic endometriosis, a dose of 2.5 mg once a day is commonly used 3.
- For programming of ovarian stimulation in IVF/GIFT cycles, a dose of 10 mg/day orally is used, starting between days 2 and 4 of the cycle 4.
- For uterine bleeding in postmenopausal women, continuous-combined formulations of 17beta-estradiol (E2) 1 mg and norethindrone acetate 0.1 mg, 0.25 mg, or 0.5 mg are used 5, 6.
- For rectovaginal endometriosis, a dose of 2.5mg/day up to 5mg/day is used for long-term treatment 7.
Efficacy and Acceptability
- Norethindrone has been shown to be effective in reducing symptoms of endometriosis, including pain and bleeding 3, 7.
- The treatment is generally well-tolerated, with a low incidence of side effects 3, 5, 6, 7.
- Long-term treatment with norethindrone acetate has been shown to be safe and effective for women with rectovaginal endometriosis 7.
Specific Conditions
- For endometriosis, norethindrone acetate has been shown to be effective in reducing pain symptoms and improving quality of life 3, 7.
- For uterine bleeding in postmenopausal women, continuous-combined formulations of E2 and norethindrone acetate have been shown to reduce the incidence of bleeding and endometrial hyperplasia 5, 6.
- For infertility, norethindrone acetate has been used to program ovarian stimulation in IVF/GIFT cycles, with good results 4.