Can a patient switch to norethindrone (progestin) and stop taking Lo Loestrin Fe (ethinyl estradiol and norethindrone acetate) to stop breakthrough bleeding?

Switching from Lo Loestrin Fe to Norethindrone for Breakthrough Bleeding

Switching to norethindrone-only (progestin-only pill) will likely worsen breakthrough bleeding rather than improve it, as progestin-only pills are specifically associated with irregular bleeding in approximately 40% of users. 1

Why This Switch Is Counterproductive

Progestin-Only Pills Cause More Breakthrough Bleeding

• Progestin-only pills (POPs) containing norethindrone are associated with irregular bleeding and breakthrough bleeding as a known adverse effect 1
• Approximately 40% of women taking progestin-only pills experience vaginal bleeding/spotting, with 25% finding this severe enough to discontinue the medication 2, 3
• POPs need to be taken at the same time each day and have remained less popular than combined hormonal contraceptives specifically because of irregular bleeding patterns 1

Combined Pills Like Lo Loestrin Fe Have Lower Bleeding Rates

• Combined hormonal contraceptives (which Lo Loestrin Fe is) reduce breakthrough bleeding to approximately 10% of users, compared to 40% with progestin-only pills 3
• The estrogen component in combined pills was historically added specifically to reduce breakthrough bleeding that occurred with progestin-only formulations 1

Evidence-Based Management of Breakthrough Bleeding on Combined Pills

First-Line Treatment Approach

• Rule out pregnancy first before treating any breakthrough bleeding 4
• Screen for sexually transmitted infections (chlamydia and gonorrhea), as these can cause bleeding 4
• Assess for drug interactions that reduce contraceptive hormone levels (rifampin, anticonvulsants like carbamazepine, phenytoin, topiramate, St. John's wort) 1, 5
• Evaluate for new uterine pathology (fibroids, polyps, cervical lesions) 4
• Counsel about smoking cessation, as cigarette smoking increases breakthrough bleeding risk 4

Treatment Algorithm for Breakthrough Bleeding

For spotting or light bleeding:

• Start with NSAIDs for 5-7 days during bleeding episodes as first-line treatment 4
• If NSAIDs fail, add low-dose combined oral contraceptives (30-35 μg ethinyl estradiol) for 10-20 days during bleeding 4

For heavy or prolonged bleeding:

• Proceed directly to hormonal treatment with low-dose COCs (30-35 μg ethinyl estradiol) for 10-20 days during bleeding episodes 4

Alternative: Adding Norethindrone TO Combined Pills

• If switching contraceptives is not desired, adding 5 mg norethindrone acetate (Primolut-nor) to the existing combined pill significantly reduces breakthrough bleeding 2
• This approach showed significant decrease in bleeding frequency at 2,4, and 6 weeks compared to continuing single-dose POP or doubling POP dose 2

Critical Counseling Point

• Unscheduled bleeding is most common in the first 3-6 months of any hormonal method, and enhanced counseling about expected bleeding patterns reduces discontinuation rates 4
• If the patient has only recently started Lo Loestrin Fe, expectant management may be appropriate before making changes

Common Pitfall to Avoid

Do not switch from a combined hormonal contraceptive to a progestin-only pill to manage breakthrough bleeding—this reverses the historical development of contraceptives and will likely worsen the bleeding problem that prompted the switch in the first place. 1, 2