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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 ?
The researchers examined cellular changes in the endometrium, analyzing samples taken from 15 women before and three months after the insertion of the Mirena IUS.
Susan, from Bristol, who longed for another child, claims she later found she was not offered Mirena because the NHS budget was overspent.
FEAR: Scots are snubbing surgery for other contraceptive methods; BOOST: The Mirena device
Mirena is a coil that releases a small dose of progestogen hormone (levonorgestrel) into the uterus and works for up to five years at a time.
IT LOOKS like a tiny fishing hook but the new contraceptive Mirena is catching on in a big way worldwide.
5 mg and Mirena (levonorgestrel-releasing intrauterine system) 52 mg to low-income women who meet eligibility criteria.
The panel concluded that the evidence supports the use of progestin-only pills, Depo-Provera injection, Implanon insertion, and Mirena IUD placement immediately after birth.
Dear God, look at what they've done," said Shpresa Mirena when for the first time she saw the charred and shattered ruins of her home in a burned out village, near Pristina.
A YOU are referring to the Mirena Intra Uterine system.
Pre-Settlement Case Funding Firm announces new program focus for women who used NuvaRing Birth Control devices, as well as Yaz, Yasmin, Occella, and Mirena IUD contraceptive products.
The Mirena levonorgestrel intrauterine system, which releases levonorgestrel to the endometrium over 5 years, has been associated with improvement in menor-rhagia and decreased uterine size and bleeding with fibroids, "which is probably why we're seeing it being used more and more," Dr.