Postinor

Indications

Levonorgestrel is a hormone used to prevent pregnancy. On its own as a single high-dose tablet it is used as emergency contraception after unprotected sex or when regular contraception has failed (for example a split condom or missed pills). In lower doses it is part of regular birth control pills, often combined with Ethinylestradiol, and it is also used in contraceptive implants and hormonal intrauterine devices.

How It Works

As emergency contraception it mainly delays or stops the release of an egg from the ovary. In regular contraceptives it also thickens the mucus at the neck of the womb so sperm cannot pass easily. It does not end a pregnancy that has already started.

Dosage and Administration

Emergency contraception, adults: 1.5 mg as a single dose (one 1.5 mg tablet, or two 0.75 mg tablets taken together) as soon as possible after unprotected sex, preferably within 12 hours and no later than 72 hours (3 days). The sooner it is taken, the better it works. If you vomit within 3 hours, take another dose and contact a doctor or pharmacist. Regular contraceptive pills: follow the pack instructions or the doctor's advice. Implants and intrauterine devices are fitted by a trained doctor or nurse.

Interactions

• Medicines that speed up liver enzymes can make it less effective, including Rifampicin, Carbamazepine, Phenytoin, Phenobarbital, some HIV medicines such as Efavirenz, and St John's wort. If you have taken any of these in the last 4 weeks, ask a doctor; a different method or dose may be advised.
• Do not use it within 5 days after taking Ulipristal acetate, as each can weaken the other.
• It may raise levels of Ciclosporin.

Contraindications

• Known pregnancy (it will not work and is not an abortion pill).
• Allergy to levonorgestrel or any ingredient of the product.
• For regular long-term use: current or past breast cancer, severe liver disease, or unexplained vaginal bleeding.

Side Effects

Common: nausea, tiredness, headache, dizziness, lower abdominal pain, breast tenderness, and changes to the next period (it may come early or late, or there may be spotting).

Get urgent medical help for:

• Severe lower abdominal pain, especially with a missed or late period, fainting or shoulder tip pain (possible ectopic pregnancy, a pregnancy outside the womb).
• Swelling of the face or throat, difficulty breathing or a severe rash.
• Very heavy or prolonged bleeding.

If the next period is more than 7 days late or unusually light, take a pregnancy test.

Pregnancy and Lactation

It should not be taken by someone who is already pregnant. If pregnancy happens despite taking it, current evidence does not suggest harm to the baby. Small amounts pass into breast milk. For an emergency dose, product leaflets suggest breastfeeding just before taking it and then avoiding breastfeeding (expressing and discarding milk) for about 8 hours. Regular low-dose progestogen-only methods are suitable while breastfeeding.

Precautions and Warnings

• Emergency contraception is not a substitute for regular contraception; ask about a regular method.
• It protects only against unprotected sex that happened before the dose, not later in the same cycle; use condoms until the next period.
• It does not protect against sexually transmitted infections.
• Tell the doctor about past ectopic pregnancy, pelvic infection, severe digestive problems or liver disease.

Overdose

Taking more than advised may cause nausea, vomiting and vaginal bleeding. Serious harm is unlikely, but seek medical advice, especially for a child.

Therapeutic Class

Progestogen (hormonal contraceptive).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.