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1. 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 If examination reveals papilledema or retinal vascular lesions, medication should be withdrawn. There have been reports of retinal vascular coincident with the use of progestins.
2. Because of the occasional occurrence of thrombophlebitis and pulmonary embolism in patients taking progestogens, the physician should be alert to the earliest manifestations of the disease. Care should be used when prescribing progestins to a population that may be predisposed to thrombotic disorders (e.g., past history of thrombotic events, thrombophilia, obesity, cardiovascular disease, prolonged immobilization).
3. Several reports suggest an association between intrauterine exposure to progestational drugs in the first trimester of pregnancy and genital abnormalities in male and female fetuses. The risk of hypospadias, 5 to 8 per 1,000 male births in the general population, may be approximately doubled with exposure to these drugs. There are insufficient data to quantify the risk to exposed female fetuses, but insofar as some of these drugs induce mild virilization of the external genitalia of the female fetus, and because of the increased association of hypospadias in the male fetus, it is prudent to avoid the use of these drugs during the first trimester of pregnancy.

General Precautions

1. The pretreatment physical examination should include special reference to breasts and pelvic organs, as well as a Papanicolaou smear.
2. Because this drug may cause some degree of fluid retention, conditions which might be influenced by this factor, such as epilepsy, migraine, asthma, cardiac or renal dysfunctions, require careful observation.
3. In cases of breakthrough bleeding, as in all cases of irregular bleeding per vagina, nonfunctional causes should be borne in mind. In cases of undiagnosed vaginal bleeding, adequate diagnostic measures are indicated.
4. Patients who have a history of psychic depression should be carefully observed and the drug discontinued if the depression recurs to a serious degree.
5. Any possible influence of prolonged progestogen therapy on pituitary, ovarian, adrenal, hepatic, or uterine functions awaits further study.
6. Data suggest that progestin therapy may have adverse effects on lipid and carbohydrate metabolism. The choice of progestin, its dose, and its regimen may be important in minimizing these adverse effects, but these issues will require further study before they are clarified. Women with hyperlipidemias and/or diabetes should be monitored closely during progestin therapy.
7. The age of the patient constitutes no absolute limiting factor, although treatment with progestogens may mask the onset of the climacteric.
8. The pathologist should be advised of progestogen therapy when relevant specimens are submitted.

Information for the Patient

See PATIENT INFORMATION section.

Carcinogenesis, Mutagenesis, and Impairment of Fertility

Some beagle dogs treated with medroxyprogesterone acetate developed mammary nodules. Although nodules occasionally appeared in control animals, they were intermittent in nature, whereas nodules in treated animals were larger and more numerous, and persisted. There is no general agreement as to whether the nodules are benign or malignant. Their significance with respect to humans has not been established.

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 genital abnormalities in male and female fetuses. Hypospadias occurs in about 5 to 8 per 1, 000 male births and is about doubled with exposure to these drugs. Some progestational drugs induce mild virilization of the external genitalia of female fetuses.

Nursing Mothers

Detectable amounts of progestogens have been identified in the milk of mothers receiving them. The effect of this on the nursing infant has not been determined.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Last reviewed on RxList: 3/31/2009
This monograph has been modified to include the generic and brand name in many instances.