Patient Leaflet Updated 20-Aug-2024 | Bayer plc
Mirena
Date of insertion = X Spotting = ○ Bleeding = ●
Month 1
Month 2
Month 3
Month 4
Mirena®
20 micrograms/24 hours intrauterine delivery system
(levonorgestrel)
Please read this booklet carefully before you decide to have Mirena fitted.
It provides you with some useful information about Mirena. The information in this booklet applies only to Mirena. If you have any questions or are not sure about anything, please ask your doctor or nurse.
1. What Mirena is and what it is used for page number
2. What you need to know before you use Mirena page number
3. How and when Mirena is used page number
4. Possible side effects page number
5. Further information page number
Mirena is an intrauterine system (IUS) placed inside the womb (uterus) where it slowly releases the hormone levonorgestrel. It can be used in the following three ways:
1. As an effective long-term and reversible method of contraception.
Mirena should be removed no later than 8 years after insertion when used for contraception.
2. For reducing menstrual blood flow, if you suffer from heavy periods (heavy menstrual bleeding).
Mirena should be removed no later than 8 years after insertion when used for heavy menstrual bleeding. Inform your healthcare professional if your symptoms return.
3. If you are going through the menopause Mirena can be used in conjunction with an oestrogen as part of a hormone replacement therapy (HRT) regimen to protect the lining of your womb.
Not so much is known about how well Mirena protects the lining of the womb beyond 4 years of use in women who are taking oestrogen to treat menopausal symptoms. Therefore, if you are using it in this way, your doctor or nurse will remove your Mirena no later than 4 years after insertion. Your doctor will be able to advise you further.
Children and adolescents
Mirena is not indicated for use before the first menstrual bleeding (menarche).
How does Mirena work?
As a contraceptive:
The hormone in Mirena prevents pregnancy by:
There are also some effects on the lining of the womb caused by the presence of the T-shaped frame of the Mirena device.
In the treatment of heavy menstrual bleeding:
The hormone in Mirena reduces menstrual bleeding by controlling the monthly development of the womb lining, making it thinner, so that there is less bleeding every month.
As part of an HRT regimen:
The menopause is a gradual process which usually takes place between the ages of about 45 and 55. Although the menopause is natural, it often causes distressing symptoms such as hot flushes and night sweats. These symptoms are due to the gradual loss of the female sex hormones (oestrogen and progestogen) produced by the ovaries.
Oestrogens can be used to relieve the menopausal symptoms. However, taking oestrogens alone increases the risk of abnormal growth or cancer of the lining of the womb. Taking a progestogen, such as the hormone in Mirena (levonorgestrel), as part of an HRT regimen lowers this risk by protecting the lining of the womb.
Your doctor or nurse will carry out some tests before you have Mirena fitted to make sure that it is suitable for you to use. This will include a pelvic examination so that pregnancy and sexually transmitted diseases can be excluded and may also include other examinations such as a breast examination, if your doctor or nurse feels this is appropriate.
Genital infections will need to be successfully treated before you can have Mirena fitted.
Mirena is not suitable for use as an emergency contraceptive (postcoital contraceptive).
If Mirena is to be fitted for HRT use your doctor will firstly carry out an assessment of your symptoms to ensure that treatment is only initiated for symptoms that adversely affect your quality of life. Such an assessment should be repeated by your doctor at least annually. You should also consult the Patient Information Leaflet of the oestrogen product that is to be used in conjunction with Mirena before starting your HRT regimen as there are some important risk factors associated with HRT that you should consider, such as the risk of endometrial cancer, breast cancer and blood clots.
If you have epilepsy, tell the doctor or nurse fitting the Mirena because, although rare, a fit can occur during insertion or removal.
You may feel pain or have some bleeding during insertion. Some women might feel faint after the procedure. This is normal and your doctor or nurse will tell you to rest for a while.
Do not use Mirena and please tell your doctor or nurse if you:
Mirena must not be used as part of an HRT regimen if you have had a stroke, heart attack or any heart problems.
Mirena may not be suitable for all women.
Consult your doctor or nurse if you:
You may still be able to use Mirena if you have or have had some of these conditions. Your doctor or nurse will advise you.
You must also tell your doctor or nurse if any of these conditions occur for the first time while you have Mirena in place.
Psychiatric disorders
Some women using hormonal contraceptives including Mirena have reported depression or depressed mood. Depression can be serious and may sometimes lead to suicidal thoughts. If you experience mood changes and depressive symptoms contact your doctor for further medical advice as soon as possible.
You must see a doctor or nurse as soon as possible if you develop painful swelling in your leg, sudden chest pain or difficulty breathing as these may be a sign of a blood clot. It is important that any blood clots are treated promptly.
You must also see a doctor without delay if you develop persistent lower abdominal pain, fever, pain during sexual intercourse or abnormal bleeding. If you get severe pain or fever shortly after Mirena has been inserted, you may have a severe infection which must be treated immediately.
It is advisable to give up smoking when using hormone containing products such as Mirena.
Use of sanitary pads is recommended. If tampons or menstrual cups are used, you should change them with care so as not to pull the threads of Mirena. If you think you may have pulled Mirena out of place (see section 3 ‘How and when Mirena is used - How can I tell whether Mirena is in place?’), avoid intercourse or use a barrier contraceptive (such as condoms), and contact your doctor.
Your doctor or nurse can remove Mirena at any time. Unless you wish to get pregnant the removal should be carried out during the first 7 days of your period. Otherwise it is important to use another form of contraception (e.g. condoms) in the 7 days leading up to the removal as intercourse during this week could lead to pregnancy after Mirena is removed.
If you do wish Mirena to be removed so that you can get pregnant your usual level of fertility is expected to return after it is removed. Studies have suggested that in women who discontinue Mirena (in order to become pregnant) the pregnancy rate at one year is similar to those who do not use contraception.
The effect of hormonal contraceptives such as Mirena may be reduced by medicines that increase the amounts of enzymes made by the liver. Please tell your doctor or nurse if you are taking any:
Please tell your doctor or nurse if you are taking or have recently taken any other medicines, including medicines obtained without prescription.
Mirena should not be used during pregnancy or if you think you are pregnant.
It is very rare for women to become pregnant with Mirena in place.
Missing a period may not mean that you are pregnant as some women may not have periods at all while using Mirena. However, in order to exclude the possibility of pregnancy, you should consider a pregnancy test if you have not had a period for 6 weeks. If this test is negative there is no need to carry out another test, unless you have other signs of pregnancy, e.g. sickness, tiredness or breast tenderness.
If you become pregnant with Mirena in place, you should see your healthcare professional immediately to have Mirena removed. The removal may cause a miscarriage. However, if Mirena is left in place during pregnancy, not only is the risk of having a miscarriage higher, but also the risk of preterm labour. If Mirena cannot be removed, ectopic pregnancy should be excluded and talk with your healthcare professional about the benefits and risks of continuing the pregnancy. If the pregnancy is continued, you will be closely monitored during your pregnancy and you should contact your doctor right away if you experience stomach cramps, pain in your stomach or fever.
Mirena contains a hormone, called levonorgestrel, and there have been isolated reports of effects on the genitalia of female babies if exposed to levonorgestrel intra-uterine devices while in the womb.
Very small amounts of the hormone in Mirena are found in breast milk but the levels are lower than with any other hormonal contraceptive method. Please ask your doctor or nurse for advice before breastfeeding.
Mirena should be inserted by a healthcare professional who is experienced in Mirena insertion. They will explain the fitting procedure and any risks associated with its usage. You will then be examined by your doctor or nurse before Mirena is fitted. If you have any concerns over its usage you should discuss it with them.
Starting to use Mirena:
Starting to use Mirena after giving birth:
Starting to use Mirena after an abortion:
Replacing Mirena
Changing from another contraceptive method (such as combined hormonal contraceptive, implant)
You should have it checked 6 weeks after it is fitted. Your doctor may determine how often and what kind of check-ups are required in your particular case. If you received a patient reminder card from your doctor bring this with you to every scheduled appointment.
Gently put a finger into your vagina and feel for the two thin threads attached to the lower end of Mirena. Your doctor or nurse will show you how to do this.
Do not pull the threads because you may accidentally pull it out. If you cannot feel the threads, contact your doctor or nurse as soon as possible and in the meantime avoid intercourse or use a barrier contraceptive (such as condoms). The threads may have simply drawn up into the womb or cervical canal. If the threads still cannot be found by your doctor or nurse, they may have broken off, or Mirena may have come out by itself, or in rare cases it may have perforated the wall of your womb (uterine perforation, see section 4). It may be necessary for you to have an ultrasound scan or x-ray to locate Mirena.
Contact your doctor or nurse if you can feel the lower end of Mirena itself or you or your partner feel pain or discomfort during sexual intercourse.
The muscular contractions of the womb during menstruation may sometimes push the IUS out of place or expel it. This is more likely to occur if you are overweight at the time of IUS insertion or have a history of heavy periods. If the IUS is out of place, it may not work as intended and therefore, the risk of pregnancy is increased. If the IUS is expelled, you are not protected against pregnancy anymore.
Possible symptoms of an expulsion are pain and abnormal bleeding but Mirena may also come out without you noticing. As Mirena decreases menstrual flow, increase of menstrual flow may be indicative of an expulsion.
It is recommended that you check for the threads with your finger, for example while having a shower. See also previous section ‘How can I tell whether Mirena is in place?’. If you have signs indicative of an expulsion or you cannot feel the threads, you should use another contraceptive (such as condoms), and consult your healthcare professional.
Some women feel dizzy or faint during or after Mirena is removed. You may experience some pain and bleeding during removal of Mirena.
Contraception:
Mirena should be removed no later than 8 years after insertion when used for contraception.
Mirena can be easily removed at any time by your healthcare professional, after which pregnancy is possible. Unless you plan to have a new system or an intra-uterine device fitted immediately, it is important to use another form of contraception (e.g. condoms) for at least 7 days leading up to the removal. Intercourse during this week could lead to pregnancy after Mirena is removed. If you do not wish to continue using the same method, ask your doctor for advice about other reliable contraceptive methods.
Heavy menstrual bleeding:
Mirena should be removed no later than 8 years after insertion when used for heavy menstrual bleeding. Inform your healthcare professional if your symptoms return, Mirena will then be removed or replaced.
Using Mirena as part of an HRT regimen:
Mirena should be removed no later than 4 years after insertion when you are using Mirena as part of an HRT regimen.
Mirena will affect your menstrual cycle.
For all uses of Mirena:
You may have lighter periods or painful periods or some spotting (light bleeding in between periods) and irregular bleeding during the first few months after Mirena is fitted.
You may have prolonged or heavy bleeding or an increase in the frequency of bleeding, usually in the first 2 to 3 months, before a reduction in blood loss is achieved.
Overall you are likely to have fewer days bleeding in each month and you might eventually have no periods at all. This is due to the effect of the hormone (levonorgestrel) on the lining of the womb.
If you develop any new vaginal bleeding or experience a change in bleeding patterns after using Mirena for some time, consult your doctor or nurse as this could be a sign that Mirena has been expelled or is not working well enough for you.
There is a calendar on the last page of this patient information booklet. Your doctor or nurse may ask you to fill this in to check your pattern of bleeding. If you are asked to do so, mark the date of insertion with an “X” in the appropriate date square. Mark days of spotting with “o” and bleeding with “•”.
If you have had Mirena fitted for heavy menstrual bleeding:
You should have lighter periods after 3 to 6 months. If you do not have lighter periods after 3 to 6 months, alternative treatments should be considered.
If you have had Mirena fitted for HRT use:
If you develop any new vaginal bleeding or experience a change in bleeding patterns after using Mirena for some time, consult your doctor or nurse as this could be a sign that Mirena has been expelled, is not working well enough for you or there are changes to your womb.
Taking any medicine carries some risk of side effects. With Mirena these are most common during the first months after it is fitted and decrease as time goes on.
Very Common (more than 1 in 10 women)
Common (less than 1 in 10 women)
Uncommon (less than 1 in 100 women)
Rare (less than 1 in 1000 women)
Unknown frequency
Your partner may feel the removal threads during intercourse.
Every woman is at risk of breast cancer, but it is rare in women under the age of 40. Breast cancer has been reported in Mirena users, although the risk and frequency are unknown.
In pre-menopausal women, the frequency of developing breast cancer whilst using Mirena is possibly similar to that associated with using Combined Oral Contraceptives, but the evidence for this is less conclusive.
In post-menopausal women, using hormone replacement therapy (HRT) slightly increases the risk of breast cancer. Although the risk of developing breast cancer is higher with combined oestrogen/progestogen HRT, than with oestrogen-only HRT, the risk of breast cancer developing when Mirena is prescribed to provide the progestogen component of HRT is not yet known. The patient information leaflet of the oestrogen component of the treatment should also be consulted for additional information.
It is important to regularly check your breasts and you should contact your doctor if you feel any lump in your breasts. You should also tell your doctor if a close relative has or ever had breast cancer.
If any of the side effects gets serious, or if you notice any side effects not listed in this booklet, please tell your doctor or nurse.
If you get any side effects talk to your doctor, pharmacist, nurse or other healthcare professional. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: https://yellowcard.mhra.gov.uk or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine. For long-acting products like Mirena, please report information of when Mirena was inserted and removed, as applicable.
Mirena contains 52 milligrams of levonorgestrel. The hormone is contained within a substance called polydimethylsiloxane. This is surrounded by a membrane (skin) also made of polydimethylsiloxane (which contains silica, colloidal anhydrous).
The Mirena T-shaped frame also contains barium sulphate so that it can be seen on X-rays.
Mirena consists of a small white T-shaped frame made from a plastic called polyethylene.
There are two fine brown threads, made of iron oxide and polyethylene, attached to the bottom of the frame. These allow easy removal and allow you or your doctor or nurse to check that Mirena is in place.
Each sterile pack contains one Mirena and should not be opened until required.
PL Number: 00010/0547
This booklet was revised in April 2024.
Other sources of information
Detailed and updated information on this medicine is available by scanning the QR Code included in the package leaflet, outer carton and patient reminder card with a smartphone. The same information is also available on the following URL: www.pi.bayer.com/mirena/uk and on the website of the MHRA (https://www.gov.uk/pil-spc).
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