What is norethindrone?
Norethindrone, also known as norethisterone is a man-made version of progesterone, the female hormone that plays a vital role in regulating ovulation and menstruation. 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 used to prevent pregnancy.
Norethindrone may also be used for other purposes not listed in this medication guide.
How does Norethindrone work?
Norethindrone works by mimicking the effects of your natural progesterone. Your progesterone levels naturally fluctuate throughout your monthly menstrual cycle. Norethindrone is rapidly and completely absorbed after oral administration, peak plasma concentration occurring in the majority of subjects between 1 and 3 hours. Due to first-pass metabolism, blood levels after oral administration are 60% of those after i.v. administration.
How should I take norethindrone?
Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.
Carefully follow your doctor’s dosing instructions about when to start taking norethindrone for contraception if you are switching from a combination birth control pill (estrogen and progestin).
If you take norethindrone for contraception: Take one pill every day, no more than 24 hours apart. You may get pregnant if you do not take one pill daily.
You may need to use backup birth control (such as condoms with spermicide) if you are sick with vomiting or diarrhea, or if you are 3 or more hours late in taking your daily dose.
If you take norethindrone for menstrual disorders or abnormal vaginal bleeding: You will most likely take the medicine for only 5 to 10 days. Vaginal bleeding will occur 3 to 7 days after your last dose.
If you take norethindrone for endometriosis: Norethindrone is usually taken daily long-term for several months. Your doctor may occasionally change your dose.
Your doctor should check your progress on a regular basis. Self-examine your breasts for lumps on a monthly basis, and have regular mammograms.
Report any unusual vaginal bleeding right away.
Norethindrone can affect the results of certain medical tests. Tell any doctor who treats you that you are using norethindrone.
Store this medication at room temperature away from moisture, heat, and light.
What Happens When You Stop Taking Norethindrone?
What happens when you stop taking norethindrone depends on the purpose for which you are using the medication.
If your doctor prescribed norethindrone to treat endometriosis, stopping the medication can result in the return of symptoms such as:
- Severe, debilitating abdominal cramps.
- Pelvic pain, usually worse during a period.
- Long periods.
- Heavy menstrual flow.
- Nausea and/or vomiting.
- Pain/cramping during or after sexual intercourse.
- Bowel and urinary disorders.
- Painful bowel movements or urination during menstruation
If you are taking the drug as a form of contraception, stopping the medication may result in pregnancy if you have sexual intercourse. Norethindrone can be prescribed for delaying menstruation. Taken at a dose of 5mg three times daily, starting two to three days before menstruation is expected, it stabilizes the endometrium. Stopping norethindrone for this purpose will result in the return of menstruation or regular periods.
