Mirena® is a hormone-releasing intrauterine device (IUD). Mirena is a small, T-shaped device that releases the hormone levonogestrel, and is used for birth control, heavy menstrual periods, and to prevent excessive build of the lining of the uterus in those on estrogen replacement therapy. It is one of the most effective forms of birth control with a one-year failure rate around 0.2%. The device is placed in the uterus and lasts three to five years. Following removal fertility returns quickly.
Prescription Name and Overview
Mirena® (levonorgestrel-releasing intrauterine system) consists of a T-shaped polyethylene frame (T-body) with a steroid reservoir (hormone elastomer core) around the vertical stem. The reservoir consists of a white or almost white cylinder, made of a mixture of levonorgestrel and silicone (polydimethylsiloxane), containing a total of 52 mg levonorgestrel. The reservoir is covered by a semi-opaque silicone (polydimethylsiloxane) membrane. The T-body is 32 mm in both the horizontal and vertical directions. The polyethylene of the T-body is compounded with barium sulfate, which makes it radiopaque. A monofilament brown polyethylene removal thread is attached to a loop at the end of the vertical stem of the T-body.
Generic Name and Overview
Levonorgestrel is a progestogen used in a variety of contraceptive products. Low doses of levonorgestrel can be administered into the uterine cavity with the Mirena intrauterine delivery system. Initially, levonorgestrel is released at a rate of approximately 20 μg/day. This rate decreases progressively to half that value after 5 years.
OTC Name and Overview
Manufacturer
Bayer Healthcare Pharmaceuticals is the manufacturer of Mirena.
Labeled Indications
Mirena is indicated for intrauterine contraception for up to 5 years. Thereafter, if continued contraception is desired, the system should be replaced. Mirena is recommended for women who have had at least one child.
Active Ingredients
The active ingredient in Mirena is the hormone levonogestrel.
What Is It Used For?
How Does it Work?
Levonorgestrel is a progestogen used in a variety of contraceptive products. Low doses of levonorgestrel can be administered into the uterine cavity with the Mirena intrauterine delivery system. Initially, levonorgestrel is released at a rate of approximately 20 μg/day. This rate decreases progressively to half that value after 5 years. Mirena has mainly local progestogenic effects in the uterine cavity. Morphological changes of the endometrium are observed, including stromal pseudodecidualization, glandular atrophy, a leukocytic infiltration and a decrease in glandular and stromal mitoses. Ovulation is inhibited in some women using Mirena.
The local mechanism by which continuously released levonorgestrel enhances contraceptive effectiveness of Mirena has not been conclusively demonstrated. Studies of Mirena prototypes have suggested several mechanisms that prevent pregnancy: thickening of cervical mucus preventing passage of sperm into the uterus, inhibition of sperm capacitation or survival, and alteration of the endometrium.
What are the Approved Uses?
Production Anecdotes / History
Precautions
Careful and objective counseling of the patient prior to insertion regarding the expected bleeding pattern, the possible inter-individual variation in changes in bleeding, including amenorrhea, and the etiology of the changes may have an effect on the frequency of patient-requested removal.
Mirena should be used with caution in patients who have:
- coagulopathy or are receiving anticoagulants
- migraine, focal migraine with asymmetrical visual loss or other symptoms indicating transient cerebral ischemia
- exceptionally severe headache
- marked increase of blood pressure
- severe arterial disease such as stroke or myocardial infarction
Long-Term Use Considerations
Mirena is only recommended for 5 years. Afterwards, the device must be removed or replaced.
Drug Interactions
The influence of drugs on the contraceptive efficacy of Mirena has not been studied. The metabolism of progestogens may be increased by concomitant use of substances known to induce drug-metabolizing liver enzymes, specifically cytochrome P450 enzymes.
When To Stop Taking
Mirena should be removed for the following medical reasons:
- menorrhagia and/or metrorrhagia producing anemia
- acquired immune deficiency syndrome (AIDS)
- sexually transmitted disease
- pelvic infection; endometritis
- symptomatic genital actinomycosis
- intractable pelvic pain
- severe dyspareunia
- pregnancy
- endometrial or cervical malignancy
- uterine or cervical perforation
Removal of the system should also be considered if any of the following conditions arise for the first time:
- migraine, focal migraine with asymmetrical visual loss or other symptoms indicating transient cerebral ischemia
- exceptionally severe headache
- jaundice
- marked increase of blood pressure
- severe arterial disease such as stroke or myocardial infarction
Long-Term Side Effects
Common side effects of Mirena are:
- missed periods (amenorrhea),
- bleeding and spotting between periods,
- heavier bleeding during the first few weeks after device insertion,
- abdominal/pelvic pain,
- ovarian cysts,
- back pain,
- headache/migraine,
- nervousness,
- dizziness,
- nausea,
- vomiting,
- bloating,
- breast tenderness or pain,
- weight gain,
- changes in hair growth,
- acne,
- depression,
- changes in mood,
- loss of interest in sex,
- itching or skin rash, and
- puffiness in the face, hands, ankles, or feet.
FDA Warnings (History Of)
In 2009, The Department of Health and Human Services published a letter under the Regulatory Review Officer Division of Drug Marketing, Advertising, and Communications regarding Mirena’s promotional materials. A Mirena representative had made claims suggesting Mirena would add “simplicity” and “intimacy” to relationships. However, the product’s warning label suggested otherwise.
Mirena product labeling indicated at least 5% of clinical patients experienced:
- Decreased libido
- Abdominal or pelvic pain
- Nausea
- Headache
- Nervousness
- Depressed mood
The FDA researcher also concluded the claims by the Mirena representative that suggested Mirena helped users “look and feel great” were false. This was made apparent with commonly-reported side effects such as irregular bleeding, ovarian cysts, back pain, weight increase, breast pain or tenderness, and acne. Finally, Mirena’s claims to eliminate “monthly routines” were declared false, as the patients were instructed to check monthly if the threads attached to the product were intact.
Other Common Side Effects
Lawsuits
In 2009, Bayer, the maker of Mirena, was issued an FDA Warning Letter by the United States Food and Drug Administration for overstating the efficacy, minimizing the risks of use, and making “false or misleading presentations” about the device. From 2000 to 2013, the federal agency received over 70,072 complaints about the device and related adverse effects. As of April 2014, over 1,200 lawsuits have been filed in the United States.
https://www.accessdata.fda.gov/drugsatfda_docs/label/2008/021225s019lbl.pdf
https://www.mirena-us.com/about-mirena/
https://www.rxlist.com/mirena-side-effects-drug-center.htm
https://en.wikipedia.org/wiki/Hormonal_IUDs#Contraindications
