What surveillance is recommended for patients taking norethindrone (MICRONOR), a progestin-only contraceptive?

Surveillance for Norethindrone (MICRONOR)

For patients taking norethindrone 0.35 mg (MICRONOR), conduct annual clinical reviews once stable on therapy, with blood pressure monitoring at each visit, and no routine laboratory monitoring is required unless prompted by specific symptoms or concerns. 1

Initial Follow-Up Period

• Schedule a follow-up visit 1 to 3 months after initiating norethindrone to address persistent adverse effects (particularly irregular bleeding) or adherence issues. 2
• This early visit is critical because irregular bleeding is the most common reason for discontinuation (54.5% of discontinuations in one study). 3

Ongoing Surveillance Schedule

Annual Clinical Review

• Once established on therapy, perform a clinical review annually, paying particular attention to compliance with daily timing of pill administration. 2, 1
• No routine monitoring tests are required but may be prompted by specific symptoms or concerns. 2

Blood Pressure Monitoring

• Monitor blood pressure at each clinical visit. 1
• While hypertension is not a contraindication to progestin-only pill use, ongoing surveillance is recommended. 2

Specific High-Risk Populations Requiring Enhanced Surveillance

Women with Prior Gestational Diabetes

• For women with history of gestational diabetes (particularly Latino women), perform oral glucose tolerance testing at 1 year and at minimum every 3 years thereafter. 1
• This is critical because norethindrone 0.35 mg is associated with a 2- to 3-fold increased risk of developing type 2 diabetes in this population. 1

Breastfeeding Women

• Monitor for decreased milk production, as isolated post-market cases have been reported with progestin-only pills. 4
• Very rarely, adverse effects in the infant/child have been reported, including jaundice. 4

Symptom-Triggered Surveillance

Menstrual Pattern Changes

• Instruct patients to report prolonged episodes of bleeding, amenorrhea, or severe abdominal pain. 4
• Menstrual irregularities are expected side effects but require clinical assessment if severe or concerning. 4

Headache/Migraine Monitoring

• If a patient develops a headache or worsening migraine with a new pattern that is recurrent, persistent, or severe, discontinue norethindrone and evaluate the cause. 4
• While migraine is not a contraindication to use, new or worsening patterns require immediate assessment. 2

Laboratory Testing: When NOT Routinely Needed

• No routine endocrine testing is required (though SHBG and thyroxine concentrations may be affected by progestin-only contraceptives). 4
• No routine lipid monitoring is needed, as norethindrone has minimal effects on lipid metabolism (occasional decreases in HDL, HDL2, and apolipoprotein A-I and A-II; no effect on total cholesterol, LDL, or VLDL). 4
• No routine bone density monitoring is indicated for norethindrone 0.35 mg monotherapy, as this is a progestin-only formulation without the bone effects seen with depot medroxyprogesterone acetate. 2

Critical Counseling Points at Each Visit

Adherence Assessment

• Verify that the patient takes the pill at the same time every day, as timing is more critical than with combined hormonal contraceptives. 5, 4
• A delay of more than 3 hours may reduce contraceptive effectiveness. 5

Backup Contraception Education

• Confirm patient understanding that backup contraception (condoms/spermicides) is needed for 48 hours whenever a pill is taken 3 or more hours late. 4

Drug Interaction Review

• At each visit, review medications that may reduce norethindrone effectiveness, including rifampin, barbiturates, phenytoin, carbamazepine, felbamate, oxcarbazepine, topiramate, griseofulvin, anti-HIV protease inhibitors, and St. John's Wort. 4
• Most broad-spectrum antibiotics (except rifampin) do not affect contraceptive effectiveness. 2

Common Pitfalls to Avoid

• Do not order routine laboratory panels (CBC, metabolic panel, liver function tests) in asymptomatic patients, as these are not indicated and increase healthcare costs without benefit. 2
• Do not wait for annual visits to address irregular bleeding concerns, as this is the primary reason for discontinuation and requires timely intervention. 3
• Do not assume all patients understand the narrow window for pill timing—explicitly reinforce that norethindrone requires more precise daily timing than combined oral contraceptives. 5