Norethindrone dosing for adequate menstrual suppression in adolescents.

Objectives: We sought to study factors predictive of achieving menstrual suppression with norethindrone vs. norethindrone acetate in adolescents, as optimal dosing is unknown. Secondary outcomes included analyzing prescriber practices and patient satisfaction.

Methods: We performed a retrospective chart review of adolescents ages <18 years presenting to an academic medical center from 2010 to 2022. Data collected included demographics, menstrual history, and norethindrone and norethindrone acetate use. Follow-up was measured at one, three, and 12 months. Main outcome measures were starting norethindrone 0.35 mg, continuing norethindrone 0.35 mg, achieving menstrual suppression, and patient satisfaction. Analysis included Chi-square and multivariate logistic regression.

Results: Of 262 adolescents initiating norethindrone or norethindrone acetate, 219 completed ≥1 follow-up. Providers less often started norethindrone 0.35 mg for patients with body mass index ≥25 kg/m, prolonged bleeding, or younger age at menarche, but more often for patients who were younger, had migraines with aura, or were at risk of venous thromboembolism. Those with prolonged bleeding or older age at menarche were less likely to continue norethindrone 0.35 mg. Obesity, heavy menstrual bleeding, and younger age were negatively associated with achieving menstrual suppression. Patients with disabilities reported greater satisfaction.

Conclusions: While younger patients more often received norethindrone 0.35 mg vs. norethindrone acetate, they were less likely to achieve menstrual suppression. Patients with obesity or heavy menstrual bleeding may achieve suppression with higher doses of norethindrone acetate. These results reveal opportunities to improve norethindrone and norethindrone acetate prescribing practices for adolescent menstrual suppression.