Micronor (Norethindrone)

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Micronor 0.35mg

Product of United Kingdom
Manufactured by: Pfizer Inc
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Micronor 0.35mg
Product of United Kingdom
Manufactured by Pfizer Inc
Top Brand Choice
Top Generic Choice

Norethindrone 0.35mg

Product of Canada
Manufactured by: Sandoz
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Norethindrone 0.35mg
Product of Canada
Manufactured by Sandoz
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Micronor (Norethindrone) Dosage and Side Effects

MICRONOR is used for the prevention of pregnancy.

Proper Use of this medication

How to Take MICRONOR (Progestin-Only Pills):

    • before you start taking your pills, and
    • any time you are not sure what to do.
  3. 28-PILL PACK: 28 active pills (with a hormone) taken daily for 28 days.
  4. ALSO CHECK: the pill pack for instructions on 1) where to start and 2) direction to take pills (see package insert for illustration).
  5. You may wish to use a second method of birth control (e.g., latex or polyurethane condoms and spermicidal foam or gel) for the first seven days of the first cycle of pill use. This will provide a backup in case pills are forgotten while you are getting used to taking them.
  6. When receiving any medical treatment, be sure to tell your doctor that you are using birth control pills.
  7. MANY WOMEN HAVE SPOTTING OR LIGHT BLEEDING, OR MAY FEEL SICK TO THEIR STOMACH DURING THE FIRST THREE MONTHS ON THE PILL. If you do feel sick, do not stop taking the pill. The problem will usually go away. If it does not go away, check with your doctor or clinic. The most common side effect of progestin-only pills is a change in menstrual bleeding. Your period may be either late or early and you may have some spotting.
  8. MISSING PILLS ALSO CAN CAUSE SOME SPOTTING OR LIGHT BLEEDING, even if you make up the missed pills. You also could feel a little sick to your stomach on the days you take two pills to make up for missed pills.
    • when you start a pack late, or
    • if you are more than 3 hours late or you miss one or more progestin-only pills.
    • ANOTHER KIND OF BIRTH CONTROL (such as latex or polyurethane condoms and spermicidal foam or gel) to use as a backup in case you miss pills, and
  11. IF YOU EXPERIENCE VOMITING OR DIARRHEA, OR IF YOU TAKE CERTAIN MEDICINES, your pills may not work as well. Use a backup method, such as latex or polyurethane condoms and spermicidal foam or gel, until you can check with your doctor or clinic.
  12. IF YOU FORGET MORE THAN ONE PILL TWO MONTHS IN A ROW, talk to your doctor or clinic about how to make pill-taking easier or about using another method of birth control.

When to Start the First Pack of Pills:


  • before you start taking your pills, and
  • any time you are not sure what to do.

YOUR MICRONOR TABLETS ARE IN A 28-DAY PILL PACKAGE. With this type of birth control pill, you take 28 pills which contain only one hormone, a progestin.


  1. THE FIRST DAY OF YOUR MENSTRUAL PERIOD (BLEEDING) IS DAY 1 OF YOUR CYCLE. With MICRONOR Tablets, it is best to start your first package of progestin-only pills on the first day of your menstrual period (Day 1). Then you simply continue taking one tablet every single day until your package is empty. Without missing a day, start taking MICRONOR Tablets from your new package.
  2. If you have had a miscarriage or an abortion, you can start progestin-only pills the next day.
  3. Take one pill at the same time every day for 28 days. Begin a new pack the next day, NOT MISSING ANY DAYS ON THE PILLS. Your period should occur during the last seven days of using that pill pack. MICRONOR Tablets are taken every day, even when you are having some menstrual bleeding.


  1. For Day 1 start: Label the DISCREET Package by selecting the day label that starts with Day 1 of your menstrual period (the first day of menstruation is Day 1). For example, if your first day of menstruation is Tuesday, attach the day label that begins with TUEin the space provided.
  2. OR
  3. For Sunday start: No day label is required. The DISCREET Package is printed for a Sunday start. (The first Sunday after your period begins, or, if your period starts on Sunday, start that same day.)
  4. Place the day label in the space where you see the words "Place day label here". Having the DISCREET Package labelled with the days of the week will help remind you to take your pill every day.
  5. To begin taking your pills, start with the pill inside the red circle (where you see the word START). This pill should correspond to the day of the week that you are taking your first pill. To remove the pill, push through the back of the DISCREET Package.
  6. On the following day, take the next pill in the same row, always proceeding from left to right (→). Each row will always begin on the same day of the week.

If you are Breast-Feeding:

    1. If you are fully breast-feeding (not giving your baby any food or formula), you may start taking your pills 6 weeks after delivery.
  • If you are partially breast-feeding (giving your baby some food or formula), you should start taking your pills 3 weeks after delivery.

If you are Switching Pills:

If you are switching from the combined pills to progestin-only pills, and you were on a 21-Day regimen, take the first progestin-only pill the day after you finish the last active combined pill. If you have been on a 28-Day regimen, do not take any of the 7 inactive pills from the combined pill pack. You should know that many women have irregular periods after switching to progestin-only pills, but this is normal and to be expected.

  1. If you are switching from progestin-only pills to the combined pills, take the first active combined pill on the first day of your period, even if your progestin-only pill pack is not finished.
  2. If you are breast-feeding, you can switch to another method of birth control at any time, except do not switch to the combined pills until you stop breast-feeding or at least until 6 months after delivery.

What to do During the Month:

    1. TAKE A PILL AT THE SAME TIME EVERY DAY UNTIL THE PACK IS EMPTY. Progestin-only pills must be taken at the same time every day since its action is time dependent. Every time you take a pill late, and especially if you miss a pill, you are more likely to get pregnant.
      • Try to associate taking your pill with some regular activity such as eating a meal or going to bed.
      • Do not skip pills even if you have bleeding between monthly periods or feel sick to your stomach (nausea).
      • Do not skip pills even if you do not have sex very often.
  • Start the next pack ON THE NEXT DAY. Take one pill every day. Do not wait any days between packs.


Symptoms of overdose may include nausea, vomiting or vaginal bleeding. Available information from cases of accidental ingestion of oral contraceptives by children indicates no serious effects.

In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

Missed dose:


  1. Take a missed pill as soon as you remember you missed it.
  2. Then go back to taking progestin-only pills at your regular time.
  3. But be sure to use a backup method (such as a condom and/or a spermicide) every time you have sex for the next 48 hours.

If you are not sure what to do about the pills you have missed, keep taking progestin-only pills and use a backup method until you can talk to your doctor or clinic.

Always be sure you have on hand:

  • a backup method of birth control (such as latex or polyurethane condoms and spermicidal foam or gel) in case you miss pills, and
  • an extra, full pack of pills.

IF YOU FORGET MORE THAN ONE PILL TWO MONTHS IN A ROW, TALK TO YOUR DOCTOR OR CLINIC about ways to make pill-taking easier or about using another method of birth control.

Side Effects

Some users of birth control pills have side effects. The most common side effect of progestin-only pills is a change in menstrual bleeding. Your periods may be either early or late. You may have some spotting between periods or you may not have a period. Taking pills late or missing pills can result in some spotting or bleeding.

Less common side effects of progestin-only pills include headaches, tender breasts, nausea, vomiting, tiredness, weight gain, dizziness, acne, extra hair on your face or body, loss of hair, rash, abdominal pain, yellowing of the skin or eyes (jaundice), and tubal pregnancy.

Warnings and Precautions

Serious Warnings and Precautions

Cigarette smoking increases the risk of serious adverse effects on the heart and blood vessels. This risk increases with age and becomes significant in hormonal contraceptive users older than 35 years of age. Women should not smoke.

Birth control pills DO NOT PROTECT against sexually transmitted infections (STIs), including HIV/AIDS.

For protection against STIs, it is advisable to use latex or polyurethane condoms IN COMBINATION WITH the birth control pills.

There are also conditions that your doctor will want to watch closely or that might cause your doctor to recommend a method of contraception other than birth control pills.

BEFORE you use MICRONOR, talk to your doctor or pharmacist if the following apply to you:

  • breast disease (e.g., breast lumps) or a family history of breast cancer
  • diabetes
  • cigarette smoking
  • migraine headaches
  • depression
  • fibroid tumours of the uterus
  • pregnant or breast-feeding
  • plans for forthcoming surgery.

You should also inform your doctor about a family history of blood clots, heart attacks or strokes.

If you see a different doctor, inform him or her that you are using MICRONOR.

Tell your doctor if you are scheduled for any laboratory tests since certain blood tests may be affected by hormonal contraceptives.

Also tell your doctor if you are scheduled for MAJOR surgery. You should consult your doctor about stopping the use of MICRONOR four weeks before surgery and not using MICRONOR for a time period after surgery or during bed rest.

MICRONOR should be used only under the supervision of a doctor, with regular follow-up to identify side effects associated with its use. Your visits may include a blood pressure check, a breast exam, an abdominal exam and a pelvic exam, including a Pap smear. Visit your doctor three months or sooner after the initial examination. Afterward, visit your doctor at least once a year.

Use MICRONOR only on the advice of your doctor and carefully follow all directions given to you. You must use the birth control pill exactly as prescribed. Otherwise, you may become pregnant. If you and your doctor decide that, for you, the benefits of MICRONOR outweigh the risks, you should be aware of the following risks:

The Risks of Using MICRONOR

  1. Ectopic Pregnancy: An ectopic pregnancy is a pregnancy outside the womb. Because progestin-only pills protect against pregnancy, the chance of having a pregnancy outside the womb is very low. If you do get pregnant while taking progestin-only pills, you have a slightly higher chance that the pregnancy will be ectopic than do users of some other birth control methods.
  2. Ovarian Cysts: These cysts are small sacs of fluid in the ovary. They are more common among progestin-only pill users than among users of most other birth control methods. They usually disappear without treatment and rarely cause problems.
  3. WARNING: If you have sudden or severe pain in your lower abdomen or stomach area, you may have an ectopic pregnancy or an ovarian cyst. If this happens, you should contact your doctor or clinic immediately.
  4. Breast Cancer: Some studies in women who use combined oral contraceptives that contain both estrogen and progestin have reported an increase in the risk of developing breast cancer, particularly at a younger age and apparently related to duration of use. There are data to determine that the use of progestin-only pills may also increase this risk.
  5. In progestin-only pill (POP) users, the older the age at stopping, the more breast cancers are diagnosed.
  6. The most significant risk factors for breast cancer are increasing age and a strong history of breast cancer in the family (mother or sister). Other established risk factors include obesity, never having children, and having your first full-term pregnancy at a late age.
  7. Some women who use birth control pills may be at increased risk of developing breast cancer before menopause which occurs around age 50. These women may be long-term users of birth control pills (more than eight years) or women who start using birth control pills at an early age. In a few women, the use of birth control pills may accelerate the growth of an existing but undiagnosed breast cancer. Early diagnosis, however, can reduce the effect of breast cancer on a woman's life expectancy. The potential risks related to birth control pills seem to be small; however, a yearly breast examination by a doctor is recommended for all women.
  9. Cervical Cancer: Some studies have found an increase in the incidence of cancer of the cervix in women who use oral contraceptives. However, this finding may be related to factors other than the use of oral contraceptives and there is insufficient data to determine whether the use of progestin-only pills increases the risk of developing cancer of the cervix.
  10. Liver Tumours: In rare cases, combined oral contraceptives can cause benign liver tumours. These benign liver tumours can rupture and cause fatal internal bleeding. In addition, a possible but not definite association has been found with combined oral contraceptives and liver cancers in studies in which a few women who developed these very rare cancers were found to have used combined oral contraceptives for long periods of time. There is insufficient data to determine whether progestin-only pills increase the risk of liver tumours.
  11. Diabetic Women: Diabetic women taking progestin-only pills generally require changes in the amount of insulin they are taking. However, your physician may monitor you more closely under these conditions.
  12. Use During Pregnancy: Birth control pills should never be taken if you think you are pregnant. They will not prevent the pregnancy from continuing. There is no evidence, however, that the progestin-only pill can damage a developing child. You should check with your doctor about risks to your unborn child from any medication taken during pregnancy.
  13. Use After Pregnancy, Miscarriage or An Abortion: Your doctor will advise you of the appropriate time to start the use ofMICRONOR after childbirth, miscarriage, or therapeutic abortion.
  14. Pregnancy After Stopping MICRONOR: You will have a menstrual period when you stop taking MICRONOR. You should delay pregnancy until another menstrual period occurs within four to six weeks. Contact your doctor for recommendations on alternative methods of contraception during this time.
  15. Use While Breast-feeding: In most women, progestin-only contraceptives, such as MICRONOR, do not affect the quantity and quality of breast milk or length of lactation. However, isolated post-marketing cases of decreased milk production have been reported. Studies with various orally administered progestin-only contraceptives have shown that small amounts of progestins pass into the breast milk of nursing mothers resulting in detectable steroid levels in infant plasma.
  16. No adverse effects have been found on the health, growth or development of the infant.

Interactions with this medication

Certain drugs may interact with birth control pills to make them less effective in preventing pregnancy or cause an increase in breakthrough bleeding. You may also need to use a nonhormonal method of contraception during any cycle in which you take drugs that can make oral contraceptives less effective.

Drugs that may interact with MICRONOR include:

  • drugs used for the treatment of epilepsy (e.g., primidone, phenytoin, carbamazepine, rufinamide);
  • drugs used for the treatment of tuberculosis (e.g., rifampin, rifabutin);
  • drugs used for the HIV/AIDS (e.g., nelfinavir, ritonavir-boosted protease inhibitors, darunavir, (fos)amprenavir, lopinavir, nevirapine);
  • (fos)aprepitant (drug used for nausea);
  • bosentan (drug used for pulmonary hypertension);
  • antifungals (griseofulvin);
  • the herbal remedy St. John's wort (primarily used for the treatment of depressive moods); and
  • sedatives and hypnotics (e.g., benzodiazepines, barbiturates, chloral hydrate, glutethimide, meprobamate).

The pill may also interfere with the working of other drugs.

Please inform your doctor and pharmacist if you are taking or have recently taken any other drugs or herbal products, even those without a prescription. Also tell any other doctor or dentist who prescribes another drug (or the dispensing pharmacist) that you use MICRONOR. They can tell you if you need to use an additional method of contraception and if so, for how long.

This is not a complete list of possible drug interactions with MICRONOR. Talk to your doctor for more information about drug interactions.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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