What is the proper dosing and administration of norethindrone (progestin)?

Norethindrone Dosing and Administration Guidelines

Norethindrone should be taken as one tablet daily at the same time each day with continuous administration and no interruption between pill packs to achieve maximum contraceptive effectiveness. 1

Dosing by Indication

For Contraception

• Norethindrone 0.35 mg taken daily without interruption (continuous administration) 1, 2
• This progestin-only pill must be taken at the same time each day for optimal effectiveness 1
• Contraceptive effectiveness rates: 1.9 per 100 woman-years with regular use and 2.5 per 100 woman-years with typical use 2

For Hormone Replacement Therapy

• When combined with estradiol for postmenopausal hormone therapy:
  • Norethindrone acetate doses range from 0.1 mg to 1.0 mg daily 3, 4
  • Lower doses (0.1 mg) are effective for endometrial protection when combined with estradiol 1 mg 3
  • For transdermal estradiol (0.05 mg/day), norethindrone acetate 0.5-1.0 mg daily for 12 days each month is effective 5

For Acne Treatment

• For teens >15 years and adults: 1 pill daily at the same time for 21 days followed by 1 week of no tablets when used as part of a combined oral contraceptive 6
• Norethindrone acetate combined with ethinyl estradiol is FDA-approved for acne treatment in women who also desire contraception 6

Administration Guidelines

Timing

• Take at the same time every day for maximum effectiveness 1
• No pill-free intervals for progestin-only contraception 1, 2

Special Considerations

• For hormone replacement therapy, norethindrone can be administered:
  • Continuously (daily without interruption) 3
  • Cyclically (12-14 days per month) when combined with estrogen 5
• Breakthrough bleeding may occur, particularly in the first few months, but tends to decrease over time 4

Monitoring

• Baseline monitoring: Pregnancy status, blood pressure 6
• Ongoing monitoring: Blood pressure, health status changes 6

Potential Side Effects

• Menstrual changes: irregular bleeding, breakthrough bleeding, amenorrhea 6, 4
• Endocrine effects: breast pain/tenderness, fluid retention 6
• Gastrointestinal: abdominal cramps, nausea, weight changes 6
• Cardiovascular: edema, varicose veins aggravation 6
• Central nervous system: depression, migraine, mood changes 6

Contraindications

• Pregnancy (Category X) 6
• History of breast cancer or other hormone-sensitive cancers 6
• Active or history of arterial thromboembolic disease 6
• Undiagnosed genital bleeding 6
• Hepatic disease or tumors 6

Clinical Pearls

• Norethindrone is a first-generation progestin with some androgenic effects 6, 7
• When used for hormone replacement, lower doses (0.1-0.5 mg) are effective for endometrial protection 3
• For contraception, the 0.35 mg daily dose must be taken consistently at the same time each day 1, 2
• Norethindrone can affect bone turnover markers and lipid profiles when used at higher doses (5 mg/day) 7