Norethindrone acetate

What is Norethindrone acetate?

• Norethindrone acetate (Aygestin; Norlutate; Norlutin) a synthetic, orally active progestin, is the acetic acid ester of norethindrone.

Norethisterone acetate

Norethisterone acetate molecule ball

What are the uses of this medicine?

• Norethindrone acetate (Aygestin; Norlutate; Norlutin) is used for the treatment of secondary amenorrhea (absence of menstrual periods in women who have previously had a menstrual period who are not pregnant), the treatment of endometriosis, and the treatment of irregular menstrual periods due to hormone imbalance.

Limitations of use:

• Norethindrone Acetate Tablets USP are not intended, recommended or approved to be used with concomitant estrogen therapy in postmenopausal women for endometrial protection.

How does this medicine work?

• The orally bioavailable acetate salt of norethindrone, a synthetic progestin with some anabolic, estrogenic, and androgenic activities.
• As do all progestins, norethindrone binds to and activates nuclear progesterone receptors (PRs) in target tissues such as the pituitary and reproductive system; ligand-receptor complexes are translocated to the nucleus where they bind to progesterone response elements (PREs) located on target genes, followed by various transcriptional events and histone acetylation.
• Physiological effects include the inhibition of luteinizing hormone (LH) release, an increase in the endometrial luteal-phase, and alterations in endocervical mucus secretion.

Who Should Not Use this medicine ?

This medicine cannot be used in patients who:

• are postmenopausal, pregnant, or breastfeeding.
• History of blood clots in the legs, lungs, eyes, brain, or elsewhere, or a past history of these conditions
• Liver impairment or disease
• Known or suspected cancer of the breast
• Undiagnosed vaginal bleeding
• Hypersensitivity to norethindrone acetate tablets

What drug interactions can this medicine cause?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Be sure to mention any of the following:

• anticoagulants (blood thinners) such as warfarin (Coumadin, Jantoven)
• certain HIV protease inhibitors such as atazanavir (Reyataz, in Evotaz), darunavir (Prezista, in Prezcobix, in Symtuza), fosamprenavir (Lexiva), nelfinavir (Viracept), and ritonavir (Norvir, in Kaletra, Technivie, Viekira Pak)
• griseofulvin (Fulvicin, Gris-Peg)
• medications for seizures such as carbamazepine (Carbatrol, Epitol, Equetro, Tegretol, others), felbamate (Felbatol), oxcarbazepine (Oxtellar, Trileptal), phenobarbital, phenytoin (Dilantin, Phenytek), and topiramate (Eprontia, Qudexy, Topamax, in Qsymia, others)
• rifampin (Rifadin, Rimactane)
• St John's wort

Is this medicine FDA approved?

• Norethisterone was discovered in 1951 and was one of the first progestins to be developed.
• It was first introduced for medical use on its own in 1957 and was introduced in combination with an estrogen for use as a birth control pill in 1963.
• It is sometimes referred to as a "first-generation" progestin.
• It is available as a generic medication.
• In 2020, it was the 137th most commonly prescribed medication in the United States, with more than 4 million prescriptions.

How should this medicine be used?

Recommended dosage: For Secondary amenorrhea, abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology:

• 2.5 to 10 mg norethindrone acetate tablets may be given daily for 5 to 10 days.

For Endometriosis:

• Initial daily dosage of 5 mg norethindrone acetate tablets for two weeks.
• Dosage should be increased by 2.5 mg per day every two weeks until 15 mg per day of norethindrone acetate tablets is reached.

Administration:

• Norethindrone comes as a tablet to take by mouth.
• Norethindrone is taken on different schedules that depend on the condition that is being treated and on how well norethindrone works to treat the conditions.
• When norethindrone is used to treat endometriosis, it is usually taken once a day for 6 to 9 months or until breakthrough bleeding becomes bothersome.
• When norethindrone is used to bring on a normal cycle in women who have stopped menstruating, it is usually taken once a day for 5 to 10 days during the second half of the planned menstrual cycle.
• If you are taking norethindrone for endometriosis, your doctor will probably start you on a low dose of norethindrone and gradually increase your dose, not more than once every 2 weeks.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As Norethindrone Acetate Tablet USP, for oral administration, contains norethindrone acetate, USP 5 mg.

This medicine is available in fallowing brand namesː

• Aygestin; Norlutate; Norlutin

What side effects can this medication cause?

The most common side effects of this medicine include:

• Headache
• Breast pain
• Irregular vaginal bleeding or spotting
• Stomach/abdominal cramps/bloating
• Nausea and vomiting
• Hair loss

Other side effects include:

• High blood pressure
• Liver problems
• High blood sugar
• Fluid retention
• Enlargements of benign tumors of the uterus (“fibroids”)
• Vaginal yeast infections
• Mental depression

Serious side effects with progestin therapy may include:

• Breast lumps
• Dizziness and faintness
• Changes in speech
• Severe headaches
• Chest pain
• Shortness of breath
• Pains in your legs
• Changes in vision

What special precautions should I follow?

• 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.
• Because this drug may cause some degree of fluid retention, conditions which might be influenced by this factor, such as epilepsy, migraine, cardiac or renal dysfunctions, require careful observation.
• Discontinue norethindrone acetate tablets and call your healthcare provider right away if you experience sudden partial or complete loss of vision, blurred vision, or sudden onset of bulging eyes, double vision, or migraine.
• Use of progestational drugs, such as norethindrone acetate tablets, has been associated with changes in the blood-clotting system. These changes allow the blood to clot more easily, possibly allowing clots to form in the bloodstream. Any of these conditions may cause death or serious long-term disability. Call your healthcare provider right away if you suspect you have any of these conditions. He or she may advise you to stop using the drug.
• In cases of breakthrough bleeding, and 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.
• Patients who have a history of clinical depression should be carefully observed and the drug discontinued if the depression recurs to a serious degree.
• 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.
• Tell your doctor if you smoke or use tobacco products. Smoking may increase the risk that you will develop serious side effects of norethindrone.
• Detectable amounts of progestins have been identified in the milk of mothers receiving them. Caution should be exercised when progestins are administered to a nursing woman.

What to do in case of emergency/overdose?

• In case of overdose, call the poison control helpline of your country. In the United States, call 1-800-222-1222.

• Overdose related information is also available online at poisonhelp.org/help.
• In the event that the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services. In the United States, call 911.

Can this medicine be used in pregnancy?

• Category X.
• Norethindrone acetate tablets are not indicated during pregnancy as it may cause fetal harm when administered to pregnant women.
• There is an increased risk of minor birth defects in children whose mothers take norethindrone acetate tablets during the first 4 months of pregnancy (mild masculinization of the external genitalia of the female fetus, as well as hypospadias in the male fetus).

Can this medicine be used in children?

• Norethindrone acetate tablets are not indicated in children.

What are the active and inactive ingredients in this medicine?

Active ingredient:

• Norethindrone acetate

Inactive ingredients:

• anhydrous lactose, magnesium stearate, and microcrystalline cellulose

Who manufactures and distributes this medicine?

• TEVA PHARMACEUTICALS USA, INC.
• North Wales, PA

What should I know about storage and disposal of this medication?

• Store at 20º to 25ºC (68º to 77ºF).
• Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure.

• Dailymed label info on Norethindrone acetate
• FDA Norethindrone acetate

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