The Mirena intrauterine device (IUD) contains levonorgestrel, a female hormone that can cause changes in your cervical mucus and uterine lining, making it harder for sperm to reach the uterus and harder for a fertilized egg to attach to the uterus.
What is Mirena?
- The Mirena intrauterine device (IUD) contains levonorgestrel, a female hormone that can cause changes in your cervical mucus and uterine lining, making it harder for sperm to reach the uterus and harder for a fertilized egg to attach to the uterus. Mirena is a plastic device that contains this hormone. This device is placed in the uterus where it slowly releases the hormone to prevent pregnancy for 5 years.
- Mirena is meant for use in a woman who has had at least one child. Mirena is also used in women who have heavy menstrual bleeding and choose to use an intrauterine form of birth control.
- Levonorgestrel is a progestin hormone and does not contain oestrogen. The intrauterine device releases levonorgestrel in the uterus, but only small amounts of the hormone reach the bloodstream.
Before taking this medicine
An intrauterine device can increase your risk of developing a serious pelvic infection, which may threaten your life or your future ability to have children. Ask your doctor about your personal risk and about ways to help prevent a pelvic infection.
You should not use Mirena if you are allergic to levonorgestrel, silicone, silica, silver, barium, iron oxide, or polyethylene, or if you have:
- abnormal vaginal bleeding that has not been checked by a doctor;
- an untreated or uncontrolled pelvic infection (vaginal, cervical uterine, or bladder);
- endometriosis or a serious pelvic infection following a pregnancy or abortion within the past 3 months;
- a history of pelvic inflammatory disease (PID), unless you have had a normal pregnancy after the infection was treated and cleared;
- uterine fibroid tumors or other conditions that affect the shape of the uterus;
- past or present breast cancer, known or suspected cervical or uterine cancer;
- liver disease or liver tumour (benign or malignant);
- a recent abnormal Pap smear that has not yet been diagnosed or treated;
- a disease or condition that weakens your immune system, such as AIDS, leukemia, or IV drug abuse; or
- if you have another intrauterine device (IUD) in place.
You may need special tests to safely use Mirena if you have:
- high blood pressure, heart disease or a heart valve disorder;
- history of heart attack or stroke;
- a bleeding or blood-clotting disorder;
- migraine headaches;
- a vaginal infection, pelvic infection, or sexually transmitted disease; or
Do not use Mirena during pregnancy. This device can cause severe infection, miscarriage, premature birth, or death of the mother if left in place during pregnancy. Tell your doctor right away if you become pregnant. If you choose to continue a pregnancy that occurs while using a Mirena intrauterine device, watch for signs of infection such as fever, chills, flu symptoms, cramps, vaginal bleeding or discharge.
If you have recently had a baby and are breast-feeding, wait until your baby is at least 6 weeks old before you start using the intrauterine system.
How is Mirena used?
- Mirena is a T-shaped plastic device that is inserted through the vagina and placed into the uterus by a doctor. The device is usually inserted within 7 days after the start of a menstrual period.
- You may feel pain or dizziness during insertion of the intrauterine device. You may also have minor vaginal bleeding. Tell your doctor if you still have these symptoms longer than 30 minutes.
- The Mirena device should not interfere with sexual intercourse, wearing tampons, or using other vaginal medications recommended by your doctor.
- After each menstrual period, make sure you can still feel the removal strings. Wash your hands with soap and water, and insert your clean fingers into the vagina. You should be able to feel the strings at the opening of your cervix. Call your doctor at once if you cannot feel the strings, or if you think the device has slipped lower in your uterus or out of your uterus. A sudden increase in menstrual flow may be a sign that the device has slipped out of place.
- If you think the Mirena device is not properly in place, use a non-hormone method of birth control (condom, or diaphragm with spermicide) to prevent pregnancy until your doctor is able to replace the levonorgestrel device.
- Your doctor will need to see you within a few weeks after insertion of the device to make sure it is still in place correctly. You will also need regular annual pelvic exams and Pap smears.
- If you need to have an MRI (magnetic resonance imaging), tell your caregivers ahead of time that you have an intrauterine device in place.
- You may have irregular periods during the first 3 to 6 months of use. Your flow may be lighter or heavier, and you may eventually stop having periods after several months. Call your doctor if you miss a period or think you might be pregnant.
- Your Mirena device may be removed at any time you decide to stop using birth control. The Mirena intrauterine device must be removed at the end of the 5-year wearing time. Only your doctor should remove the Mirena intrauterine device. Do not attempt to remove the device yourself.
- Following removal of the Mirena intrauterine device, you may become pregnant right away.
Mirena dosing information
Usual Adult Dose for Contraception:
- Mirena: One 52 mg intrauterine device inserted within seven days of the onset of menstruation or immediately after first-trimester abortion. One device is effective for 5 years.
- Mirena is also indicated for the treatment of heavy menstrual bleeding in women who choose to use intrauterine contraception as their method of contraception.
What happens if I miss a dose?
- Since the Mirena intrauterine device continuously releases a low dose of levonorgestrel, missing a dose does not occur when using this form of levonorgestrel.
Mirena side effects
Get emergency medical help if you have severe pain in your lower stomach or side. This could be a sign of a tubal pregnancy (a pregnancy that implants in the fallopian tube instead of the uterus). A tubal pregnancy is a medical emergency.
The Mirena intrauterine device may become embedded into the wall of the uterus, or may perforate (form a hole) in the uterus. If this occurs, the device may no longer prevent pregnancy, or it may move outside the uterus and cause scarring, infection, or damage to other organs. Your doctor may need to surgically remove the device.
Call your doctor at once if you have:
- severe cramps or pelvic pain, pain during sexual intercourse;
- extreme dizziness or light-headed feeling;
- severe migraine headache;
- heavy or ongoing vaginal bleeding, vaginal sores, vaginal discharge that is watery, foul-smelling discharge, or otherwise unusual;
- pale skin, weakness, easy bruising or bleeding, fever, chills, or other signs of infection;
- sudden numbness or weakness (especially on one side of the body), confusion, problems with vision, sensitivity to light;
- jaundice (yellowing of the skin or eyes); or
- signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Common Mirena side effects may include:
- pelvic pain, vaginal itching or infection, irregular menstrual periods, changes in bleeding patterns or flow;
- stomach pain, nausea, vomiting, bloating;
- headache, depression, mood changes;
- back pain, breast tenderness or pain;
- weight gain, acne, changes in hair growth, loss of interest in sex; or
- puffiness in your face, hands, ankles, or feet.