What is the recommended dosing regimen for continuous contraception with norethindrone (progestin-only pill)?

Norethindrone Progestin-Only Pill (POP) Continuous Dosing

For continuous contraception with norethindrone progestin-only pills, take 0.35 mg orally once daily at the same time every day without any pill-free intervals. 1

Standard Dosing Regimen

• One tablet (0.35 mg norethindrone) taken daily at the same time without interruption between pill packs 1
• Administration is continuous with no hormone-free days or placebo pills 1
• Timing consistency is critical—POPs must be taken at the same time each day to maintain contraceptive effectiveness 2

Key Prescribing Considerations

Timing Requirements:

• Norethindrone POPs require strict adherence to daily timing due to their mechanism of action 2
• Unlike combined oral contraceptives, there is no flexibility in timing—the same time daily is essential 1

Expected Bleeding Patterns:

• Irregular bleeding is the most common side effect of norethindrone POPs 2
• Bleeding patterns are typically unpredictable and may include spotting, breakthrough bleeding, or amenorrhea 2
• Patients should be counseled that irregular bleeding does not indicate contraceptive failure 2

Efficacy Data

• Drug-effectiveness rate of 1.9 pregnancies per 100 woman-years with regular use 3
• Use-effectiveness rate of 2.5 pregnancies per 100 woman-years accounting for irregular use 3
• Seven pregnancies occurred with regular use and two with irregular use over 4,264 months of observation 3

Clinical Pitfalls to Avoid

Common Prescribing Errors:

• Do not prescribe norethindrone POP with pill-free intervals—this negates the continuous suppression mechanism 1
• Do not confuse norethindrone POP (0.35 mg) with norethindrone acetate used in hormone replacement therapy (doses of 0.5-1.0 mg) 2
• Do not assume combined oral contraceptive missed-pill rules apply—POPs have different management protocols 4

Patient Counseling Essentials:

• Emphasize that breakthrough bleeding does not mean the method is failing 2
• Warn patients that missing pills by even a few hours may compromise efficacy 2
• Advise setting daily alarms to ensure consistent timing 1

Alternative Considerations

If continuous norethindrone POP is not tolerated due to irregular bleeding, consider:

• Combined hormonal contraceptives with extended or continuous regimens (30-35 mcg ethinyl estradiol with norethindrone) for better cycle control 4
• Fourth-generation progestin-only pills (drospirenone) which may offer improved bleeding profiles, though they also require daily timing 2