Levonorgestrel (Plan B)

1. Health Canada Product Monograph — Levonorgestrel

• Levonorgestrel is used to prevent pregnancy after unprotected intercourse or a known or suspected contraceptive failure, such as a broken condom, a missed birth control pill, or an expelled intrauterine device.
• Levonorgestrel is also used for emergency contraception after sexual assault.
• It is intended for occasional emergency use only, not as a routine or ongoing method of birth control, and does not protect against future acts of unprotected intercourse.

Contraindicated in pregnancy. Confirm pregnancy status and discuss alternative therapy with the prescriber before dispensing.

• Levonorgestrel emergency contraception is not effective once pregnancy has occurred and should not be used by women who are already pregnant.
• Studies of women who inadvertently took levonorgestrel-containing contraceptives during early pregnancy have not shown harm to the fetus.
• A pregnancy test should be performed before use if pregnancy is suspected, such as when a menstrual period is already overdue.
• If a period is delayed by more than a week after taking levonorgestrel, a pregnancy test is recommended to rule out pregnancy, including ectopic pregnancy.

• Small amounts of levonorgestrel pass into breast milk.
• Progestin-only contraceptives, including levonorgestrel, have not been shown to affect milk quality, quantity, or infant growth and development in available studies.

• Levonorgestrel emergency contraception is not intended for use in postmenopausal women, and no data are available in this population.

• No data are available on use in patients under 18, and Health Canada has not authorized a specific pediatric indication; however, the product may be used by anyone of reproductive age who needs emergency contraception.

• One 1.5 mg tablet is taken by mouth as a single dose, as soon as possible and within 72 hours after unprotected intercourse.
• Levonorgestrel can be taken at any time during the menstrual cycle.
• Effectiveness is highest when taken within 24 hours of unprotected intercourse and decreases with each additional 24-hour delay.
• If vomiting occurs within 2 hours of taking the dose, the patient should contact a healthcare professional, since a replacement dose may be needed.
• If a menstrual period is delayed more than a week after taking levonorgestrel, a pregnancy test and follow-up with a healthcare professional are recommended.

If overdose is suspected, seek emergency medical attention immediately or contact your regional Poison Control Centre without delay.

• No specific data exist on levonorgestrel overdose, but nausea, vomiting, and menstrual irregularities may be more pronounced with a higher-than-recommended dose.
• Specific treatment is generally not needed after an accidental overdose; the patient should be observed, and gastric lavage may be used if considered necessary by a physician.

• Nausea may occur.
• Lower abdominal pain or cramping may occur.
• Fatigue may occur.
• Headache may occur.
• Dizziness may occur.
• Vomiting may occur.
• Breast tenderness may occur.
• Diarrhea may occur.
• Constipation may occur.
• Acne or acne flare-ups may occur.
• Muscle cramps or leg cramps may occur.
• Vaginal discharge may occur.
• Pelvic pain may occur.
• Spotting or breakthrough bleeding may occur in the days after taking the dose.
• The next menstrual period may arrive earlier or later than expected, or be heavier, lighter, or more painful than usual.

Serious side effects require immediate discussion with the prescriber or emergency care.

• There are generally no serious adverse reactions associated with levonorgestrel emergency contraception in clinical trials or post-market experience.
• A pregnancy that occurs despite use of levonorgestrel carries a small possibility of being ectopic (outside the uterus); seek urgent medical attention for severe lower abdominal pain, especially if a period is missed.
• Seek medical attention if a menstrual period is delayed by more than a week, to confirm whether pregnancy has occurred.

• Use with caution in women with diabetes, since progestins can slightly affect glucose tolerance.
• Use with caution in women with a history of liver disease, particularly if levonorgestrel needs to be used more than once, since its effects in this population are not well studied.
• Use with caution in women reporting new, worsening, or unusually severe migraine or headache during use.
• Body weight or body mass index may reduce effectiveness, but levonorgestrel should still be taken as soon as possible after unprotected intercourse regardless of weight.
• Repeat use within the same cycle or on a regular basis should prompt a discussion about more effective, ongoing contraceptive methods.
• Levonorgestrel reduces the effectiveness of latex condoms and diaphragms, so this should be considered if barrier contraception is used afterward.
• Levonorgestrel offers no protection against HIV or other sexually transmitted infections, so barrier protection should still be used for prevention.

• Contraindicated in women who are pregnant or have suspected pregnancy, since it will not be effective and is not intended to end an existing pregnancy.
• Contraindicated in women with undiagnosed abnormal vaginal bleeding until the cause has been established.
• Contraindicated in patients with known hypersensitivity to levonorgestrel or to any ingredient in the formulation.

• Liver enzyme-inducing drugs, including certain anticonvulsants such as phenytoin and carbamazepine, rifampin, and rifabutin, can reduce levonorgestrel blood levels and may reduce its effectiveness.
• Certain antiretroviral medicines, including efavirenz and ritonavir, can substantially reduce levonorgestrel levels.
• St. John's wort can reduce the effectiveness of levonorgestrel.
• Ulipristal acetate, another emergency contraceptive, should not be used together with levonorgestrel, since it can interfere with levonorgestrel's progestin activity.
• If a woman is taking a liver enzyme-inducing medication, a pregnancy test is recommended if her period is delayed, because contraceptive effectiveness may be reduced.
• No consistent effect on contraceptive steroid levels has been found with common antibiotics such as ampicillin, tetracycline, or certain macrolides in formal studies.

• Levonorgestrel can be taken with or without food; no specific timing relative to meals is required.

• Levonorgestrel should be taken as a single dose as soon as possible after unprotected intercourse, and can be taken with or without food, at any time of day.

• Store levonorgestrel tablets at room temperature, between 15°C and 30°C, and protect from high humidity.

• Levonorgestrel (Plan B) is a single-dose emergency contraceptive taken as soon as possible, and within 3 days, after unprotected sex or a birth control failure.
• It is not a routine method of birth control and does not protect against sexually transmitted infections, including HIV.
• Common effects include nausea, cramping, fatigue, headache, and a menstrual period that comes earlier, later, heavier, or lighter than usual.
• See a healthcare professional for a pregnancy test if your period is more than a week late after taking this medicine.