Is backup contraception needed when starting norethindrone (Norethindrone) on the first day of withdrawal bleeding after discontinuing Alesse (Levonorgestrel and Ethinyl Estradiol)?

Backup Contraception When Starting Norethindrone After Discontinuing Alesse

When starting norethindrone (progestin-only pill) on the first day of withdrawal bleeding after discontinuing Alesse (combined hormonal contraceptive), backup contraception is needed for 2 days.

Timing of Starting Norethindrone After Combined Hormonal Contraceptives

• When switching from a combined hormonal contraceptive (like Alesse) to a progestin-only pill (POP) like norethindrone, the timing of initiation affects whether backup contraception is needed 1
• If norethindrone is started within the first 5 days since menstrual bleeding began, no additional contraceptive protection is needed 1
• If norethindrone is started more than 5 days since menstrual bleeding began, the woman needs to abstain from sexual intercourse or use additional contraceptive protection for the next 2 days 1

Specific Guidance for Progestin-Only Pills

• Progestin-only pills like norethindrone work differently than combined hormonal contraceptives, inhibiting ovulation in only about half of cycles 1
• Peak serum steroid levels are reached about 2 hours after administration, followed by rapid distribution and elimination 1
• By 24 hours after administration, serum steroid levels are near baseline, making consistent timing of daily doses important 1
• The CDC specifically recommends 2 days of backup contraception when starting progestin-only pills after day 5 of the menstrual cycle 1

Comparing to Combined Hormonal Contraceptive Requirements

• This differs from combined hormonal contraceptives (like Alesse), which require 7 days of backup contraception when started more than 5 days after menstrual bleeding begins 1
• The shorter backup period for progestin-only pills (2 days vs. 7 days) reflects differences in their mechanism of action and time to effectiveness 1

Important Clinical Considerations

• Withdrawal bleeding after discontinuing Alesse is not a true menstrual period but rather hormone withdrawal bleeding 1
• For maximum effectiveness, norethindrone should be taken at approximately the same time each day (within 3 hours) 1
• If a progestin-only pill is taken more than 3 hours late, backup contraception should be used for the next 2 days 1
• Unlike combined hormonal contraceptives, progestin-only pills like norethindrone can be used by women with contraindications to estrogen, such as those with certain cardiovascular or neurologic conditions 2

Potential Side Effects to Monitor

• The most common side effect of norethindrone is irregular bleeding, which is also the most common reason for discontinuation 2
• Compared to combined hormonal contraceptives, progestin-only pills may have higher rates of breakthrough bleeding 3, 4
• Patients should be counseled that irregular bleeding patterns are common with progestin-only pills and may improve over time 2

Remember that taking norethindrone at the same time each day is crucial for effectiveness, and any deviation of more than 3 hours requires 2 days of backup contraception 1.