Norethindrone Acetate

Clinical summary

Indications and usage INDICATIONS AND USAGE Norethindrone acetate is indicated for the treatment of secondary amenorrhea, endometriosis, and abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, such as submucous fibroids or uterine cancer. Norethindrone acetate is not intended, recommended or approved to be used with concomitant estrogen therapy in postmenopausal women for endometrial protection. Dosage and administration DOSAGE AND ADMINISTRATION Therapy with norethindrone acetate must be adapted to the specific indications and therapeutic response of the individual patient. Secondary amenorrhea, abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology: 2.5 to 10 mg norethindrone acetate may be given daily for 5 to 10 days to produce secretory transformation of an endometrium that has been adequately primed with either endogenous or exogenous estrogen. Progestin withdrawal bleeding usually occurs within three to seven days after discontinuing norethindrone acetate therapy. Patients with a past history of recurrent episodes of abnormal uterine bleeding may benefit from planned menstrual cycling with norethindrone acetate. Endometriosis: Initial daily dosage of 5 mg norethindrone acetate for two weeks. Dosage should be increased by 2.5 mg per day every two weeks until 15 mg per day of norethindrone acetate is reached. Therapy may be held at this level for six to nine months or until annoying breakthrough bleeding demands temporary termination. Warnings and cautions WARNINGS 1. Cardiovascular disorders Patients with risk factors for arterial vascular disease (e.g., hypertension, diabetes mellitus, tobacco use, hypercholesterolemia, and obesity) and/or venous thromboembolism (e.g., personal history or family history of VTE, obesity, and systemic lupus erythematosus) should be managed appropriately. 2. Visual abnormalities Discontinue medication pending examination if there is a sudden partial or complete loss of vision or if there is sudden onset of proptosis, diplopia, or migraine. If examination reveals papilledema or retinal vascular lesions, medication should be discontinued. Pregnancy 5. Pregnancy Category X Norethindrone acetate is contraindicated during pregnancy as it may cause fetal harm when administered to pregnant women. Several reports suggest an association between intrauterine exposure to progestational drugs in the first trimester of pregnancy and congenital abnormalities in male and female fetuses. Some progestational drugs induce mild virilization of the external genitalia of female fetuses.