norethindrone /nôreth″indrōn/ , a progestin. ▪ INDICATIONS: It is prescribed in the treatment of abnormal uterine bleeding and endometriosis and is used alone or as a component in oral contraceptive medications. ▪ CONTRAINDICATIONS: Thrombophlebitis, liver dysfunction, unusual vaginal bleeding, breast cancer, or known hypersensitivity to this drug prohibits its use. It is not recommended for use during pregnancy and should be used with caution in patients with asthma, diabetes, cardiac or renal dysfunction, hyperlipidemia, migraines, seizure disorders, or psychic depression. ▪ ADVERSE EFFECTS: Among the more serious adverse effects are breakthrough bleeding, amenorrhea, GI disturbances, breast changes, and masculinization of the female fetus. The drug should be discontinued immediately if vision problems (e.g., double vision, complete or partial loss of vision) or migraine headaches appear. Progestin-only contraceptives have a higher rate of failure.
