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Levonelle (UK), Mirena, Plan B One-Step

Pharmacologic class: Contraceptive, intrauterine device (Mirena); oral contraceptive, progestin-only pill (Plan B)

Therapeutic class: Contraceptive

Pregnancy risk category X (Mirena), NR (Plan B)

Pregnancy risk category X (Mirena), NR (Plan B)


Plan B -


Unclear. Mirena may enhance local contraceptive efficacy by thickening the cervical mucus (which prevents passage of sperm into uterus), inhibiting sperm capacitation or survival, and altering the endometrium. Plan B is thought to prevent ovulation or fertilization.


Intrauterine system (Mirena): 52 mg levonorgestrel

Tablets (Plan B): 1.5 mg

Indications and dosages

Intrauterine contraception for up to 5 years; heavy menstrual bleeding for women who choose to use intrauterine contraception

Adults: One intrauterine system (Mirena) inserted into uterus for up to 5 years

Emergency contraception to prevent pregnancy

Adults: 1.5 mg (Plan B) P.O. as soon as possible within 72 hours after unprotected intercourse


• Hypersensitivity to drug or its components
• Known or suspected pregnancy
• Congenital or acquired uterine anomaly
• Acute pelvic inflammatory disease (PID) or history of PID (unless patient had subsequent intrauterine pregnancy)
• Postpartum endometritis or infected abortion within past 3 months
• Known or suspected uterine or cervical neoplasia or unresolved abnormal Papanicolaou (Pap) test
• Untreated acute cervicitis or vaginitis
• Acute hepatic disease or hepatic tumor (benign or malignant)
• Genital bleeding of unknown cause
• Conditions associated with increased risk of infection
• Genital actinomycosis
• Previously inserted intrauterine device that has not been removed
• Known or suspected breast cancer
• History of ectopic pregnancy or conditions that predispose to it

Plan B -
• Hypersensitivity to drug or its components
• Known or suspected pregnancy
• Undiagnosed abnormal genital bleeding


Use Mirena cautiously in:
• diabetes mellitus
• breastfeeding patients.

Use Plan B cautiously in:
• coagulopathy
• diabetes mellitus
• patients receiving anticoagulants concurrently.


• Know that Mirena should be inserted under aseptic conditions by health care professional familiar with procedure.
• Verify that patient isn't pregnant before Mirena insertion.
• Know that Plan B should be given as soon as possible within 72 hours of unprotected sexual intercourse. Drug isn't suitable as long-term contraceptive.

Adverse reactions

CNS: headache (Mirena, Plan B), fatigue, dizziness (Plan B), severe headache, migraine, nervousness, depression (Mirena)

CV: hypertension (Mirena)

EENT: sinusitis (Mirena)

GI: nausea, vomiting, abdominal pain (Mirena, Plan B), diarrhea (Plan B), intestinal perforation or obstruction (Mirena)

GU: breast tenderness (Mirena, Plan B); lighter or heavier menstrual bleeding (Plan B); breast pain; increased progesterone levels; ovarian cysts; dysmenorrhea; amenorrhea; spotting; erratic or prolonged menstrual bleeding; pelvic infection; vaginitis; cervicitis; dyspareunia; leukorrhea; decreased libido; abnormal Pap smear; expulsion, embedment in myometrium, adhesions, cervical or ureteral perforation (Mirena)

Hematologic: anemia (Mirena)

Hepatic: jaundice (Mirena)

Musculoskeletal: back pain (Mirena)

Respiratory: upper respiratory tract infection (Mirena)

Skin: skin disorder, acne, eczema, hair loss (Mirena)

Other: water retention, weight gain, sepsis (Mirena)


Drug-drug.Hepatic enzyme-inducing drugs (such as barbiturates, carbamazepine, phenytoin, rifampin): decreased Plan B efficacy

Drug-diagnostic tests.Glucose: altered level (Mirena)

Patient monitoring

• Monitor blood pressure.
• Watch for adverse reactions, especially changes in menstrual bleeding.
• Monitor blood glucose level in diabetic patients.
• Check liver function tests frequently.

Patient teaching

• Tell patient taking either product that drug does not prevent HIV or other sexually transmitted diseases.
• Teach patient using Mirena how to check (after menstrual period) to make sure thread still protrudes from cervix. Caution her not to pull on thread, because this could cause displacement.

Instruct patient using Mirena to immediately report fever, chills, unusual vaginal discharge, or abdominal or pelvic pain or tenderness.
• Explain that for maximum efficacy, patient should take Plan B as soon as possible after unprotected sex.
• Inform patient that Plan B isn't intended for routine contraception and doesn't terminate existing pregnancy.
• Tell patient to report adverse reactions.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.


A so-called hormonal-type intrauterine contraceptive system, consisting of a plastic T-shaped device that is inserted into the uterus and slowly releases levonorgestrel, a synthetic progesterone analogue, ensuring that the woman remains inconceivable for up to five years.

Adverse effects
Acne, back pain, breast pain/tenderness, menstrual spotting, reduced libido, dizziness, bleeding, headache, nausea, vomiting, weight gain.


A brand name for a T-shaped intrauterine contraceptive system with a hormone reservoir that slowly releases LEVONORGESTREL, providing five-year, contraception.
References in periodicals archive ?
An intrauterine system does not only bring the advantage that women do not have to think about their contraception every day, but also that it contains fewer hormones than other hormonal contraceptive options like the pill or implant.
If pregnancy should occur with LILETTA in place, remove the intrauterine system because leaving it in place may increase the risk of spontaneous abortion and preterm labor.
In addition, noting the changes in the World Health Organization's medical eligibility criteria, and possible increased risk of HIV acquisition with injectable progestogens, there is a shift in emphasis away from injectable progestogens towards alternative long-acting reversible contraceptives (Cu IUDs, intrauterine systems, subdermal implants); and, because of the possible increased risk of HIV acquisition, emphasis is given to the importance of condom use for women who choose to use injectable progestogens.
Janesh Gupta of the University of Birmingham (England) and his associates for the ECLIPSE (Effectiveness and Cost-Effectiveness of Levonorgestrel-Containing Intrauterine System in Primary Care Against Standard Treatment for Menorrhagia) Trial Collaborative Group.
In this study, we evaluate the efficacy of the levonorgestrel-releasing intrauterine system in preventing endometrial pathology in women with breast cancer treated with tamoxifen.
They said that if women's true preferences were reflected, there would be an increase in other methods such as contraceptive hormone injections and intrauterine system - where plastic device which contains a progestogen hormone is placed in the womb.
The Mirena Intrauterine System, used by European women for more than a decade, is a T-shaped device that prevents fertilization and implantation of the egg.
Medicines360 LNG20 Intrauterine System (IUD), a long-acting, reversible contraceptive, is currently in Phase III clinical trials.
Mirena[R], a levonorgestrel-releasing intrauterine system, is the newest target for mass litigation.
Think long term - Consider longacting contraceptive methods like injections, implants or an intrauterine system.
The intrauterine system (IUS) or Mirena is a plastic device that is inserted into the womb.