Norethindrone is used to treat endometriosis, a condition in which the type of tissue that lines the uterus (womb) grows in other areas of the body and causes pain, heavy or irregular menstruation (periods), and other symptoms. Norethindrone is also used to treat abnormal periods or bleeding and to bring on a normal menstrual cycle in women who menstruated normally in the past but have not menstruated for at least 6 months and who are not pregnant or undergoing menopause (change of life). Norethindrone is also used as a test to see if the body is producing certain female hormones (natural substances that affect the uterus). Norethindrone is in a class of medications called progestins. It works by stopping the lining of the uterus from growing and by causing the uterus to produce certain hormones.
Norethindrone is also used to prevent pregnancy. Norethindrone is sold under different brand names and is taken in smaller amounts when it used to prevent pregnancy. This monograph does not include information on the use of norethindrone to prevent pregnancy.
Side Effects Of Norethindrone
Norethindrone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- irregular vaginal bleeding or spotting
- changes in menstrual flow
- enlarged or tender breasts
- upset stomach
- weight changes
- difficulty falling asleep or staying asleep
- growth of hair on the face
Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:
- loss of vision
- blurred vision
- double vision
- bulging eyes
- migraine headache
- pain, warmth, or heaviness in the back of the lower leg
- shortness of breath
- coughing up blood
- sudden sharp or crushing chest pain
- heaviness in chest
- slow or difficult speech
- dizziness or faintness
- weakness or numbness of an arm or leg
- swelling of the arms, hands, feet, ankles, or lower legs
- yellowing of the skin or eyes
- mood swings
- brown patches on the face
- missed periods
- sudden, severe pain in the abdomen (the area between the chest and waist)
- difficulty breathing or swallowing
Norethindrone may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
Warnings & Precautions
Before taking norethindrone:
- tell your doctor and pharmacist if you are allergic to norethindrone, oral contraceptives (‘birth control pills), or any other medications.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention medications for seizures such as carbamazepine (Tegretol), phenobarbital (Luminal, Solfoton), and phenytoin (Dilantin); and rifampin (Rifadin, Rimactane). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have recently had surgery or have been unable to move around for any reason and if you have or have ever had breast cancer; unexplained vaginal bleeding; a missed abortion (a pregnancy that ended when the unborn child died in the uterus but was not expelled from the body); blood clots in your legs, lungs, brain, or eyes; stroke or mini-stroke; coronary artery disease (clogged blood vessels leading to the heart); chest pain; a heart attack; thrombophilia (a condition in which the blood clots more easily); seizures; migraine headaches; depression; asthma; high cholesterol; diabetes; or heart, kidney, or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking norethindrone, call your doctor immediately. Norethindrone should never be used to test for pregnancy.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking norethindrone.
- tell your doctor if you smoke cigarettes. Smoking may increase the risk that you will develop serious side effects of norethindrone.
Dosage Of Norethindrone
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. To help you remember to take norethindrone, take it at around the same time of day every day that you are scheduled to take it. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take norethindrone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
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.
Norethindrone may control your condition but will not cure it. Continue to take norethindrone even if you feel well. Do not stop taking norethindrone without talking to your doctor.
Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body’s response to norethindrone.
Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking norethindrone.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.