Nestril

Indications

Lynestrenol is a progestogen, a man-made form of the female hormone progesterone. It is used:

• at low dose (0.5 mg), as a progestogen-only birth control pill, often chosen by breastfeeding mothers and by women who cannot take oestrogen;
• at higher dose, as prescribed by a gynaecologist, for some menstrual and womb problems such as heavy or irregular periods, painful periods and endometriosis.

How It Works

As a birth control pill, Lynestrenol thickens the mucus at the neck of the womb so sperm cannot pass easily, makes the lining of the womb less suitable for pregnancy and, in many women, stops the release of an egg (ovulation). At higher doses it controls the growth of the womb lining, which helps with heavy bleeding and endometriosis.

Dosage and Administration

Birth control (0.5 mg tablet): one tablet every day at the same time, without a break between packs. Start on the first day of the period. After childbirth, start as advised by your doctor, usually from about 3 to 6 weeks after delivery.

Missed pill: if a tablet is more than 3 hours late, take it as soon as you remember, carry on as usual and use condoms for the next 2 days. If you had sex in the days before the missed pill, speak to a doctor about emergency contraception.

Menstrual and womb problems: dose and length of treatment only as prescribed by your doctor.

Vomiting within 3 to 4 hours of a tablet or severe diarrhoea can stop the pill working; follow the missed pill advice.

Interactions

Some medicines can make Lynestrenol less effective as a contraceptive, including Rifampicin, Carbamazepine, Phenytoin, Phenobarbital, Topiramate, some HIV medicines and the herbal product St John's wort. Use extra protection or another method while taking these and for 4 weeks after. Lynestrenol may change the effect of Ciclosporin. Tell your doctor about all medicines you take.

Contraindications

• Known or suspected pregnancy
• Unexplained vaginal bleeding
• Current or past breast cancer, or other cancers that depend on sex hormones
• Severe liver disease or liver tumour
• Current blood clot in the legs or lungs
• Allergy to Lynestrenol or any ingredient of the tablet

Side Effects

Common: changes in bleeding pattern (spotting, irregular, more frequent or absent periods), breast tenderness, headache, nausea, mood changes, acne and weight change. Bleeding changes often settle after a few months.

Get medical help at once for severe pain in the lower tummy (it may be a pregnancy outside the womb), pain or swelling in one leg, chest pain or sudden breathlessness, yellowing of the skin or eyes, or a severe allergic reaction.

Pregnancy and Lactation

Do not use in pregnancy; stop and see a doctor if you think you are pregnant. The low-dose birth control pill can be used while breastfeeding, as it does not reduce milk supply. Higher doses for menstrual problems are not used while breastfeeding unless your doctor advises.

Precautions and Warnings

• Take extra care if you have diabetes, high blood pressure, migraine, a past blood clot, liver problems or depression.
• The pill does not protect against sexually transmitted infections.
• Have regular check-ups while on long-term treatment.
• Tell the doctor you take Lynestrenol before surgery or long periods of bed rest.

Overdose

Overdose is not expected to cause serious harm. Nausea, vomiting or slight vaginal bleeding may occur. If a child swallows tablets or a large amount is taken, contact a doctor.

Therapeutic Class

Progestogen (female sex hormone); progestogen-only oral contraceptive.

Storage

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