Rephaston

Indications

Dydrogesterone is a man-made form of progesterone, a female hormone. Doctors use it for problems linked to low progesterone, including threatened or repeated miscarriage, support of early pregnancy in fertility treatment (luteal phase support), irregular or absent periods, heavy or irregular bleeding not caused by another disease, painful periods, endometriosis and premenstrual symptoms. It is also combined with an oestrogen in hormone replacement therapy (HRT) after the menopause to protect the lining of the womb.

How It Works

It acts like natural progesterone on the lining of the womb, helping it to develop and shed in a regular, controlled way and supporting it in early pregnancy. It does not stop ovulation at usual doses, so it is not a contraceptive.

Dosage and Administration

Tablets are usually 10 mg. How many tablets a day, and on which days of the cycle, depends on the condition being treated, so take it exactly as prescribed. In pregnancy and fertility treatment it is used only under a specialist's direction. Swallow with water, with or without food, at the same times each day.

Interactions

Medicines that speed up liver enzymes, such as Carbamazepine, Phenobarbital, Phenytoin, Rifampicin and herbal St John's wort, may make it less effective. Tell your doctor about all medicines you take.

Contraindications

• Allergy to dydrogesterone or any ingredient of the tablet.
• Known or suspected tumours that depend on progestogens, such as meningioma.
• Vaginal bleeding that has not been checked by a doctor.
• Severe liver disease or liver tumours.
• When used with an oestrogen: the conditions in which oestrogen must be avoided, such as breast cancer, past blood clots or stroke.

Side Effects

Common: headache or migraine, nausea, breast tenderness, bloating, mood changes and spotting or changes in period bleeding.

Get urgent medical help if you have signs of an allergic reaction (swelling of the face or throat, difficulty breathing), yellow skin or eyes, a sudden severe headache or problems with vision or speech, or, especially when taken with an oestrogen, pain and swelling in one leg, chest pain or sudden breathlessness.

Pregnancy and Lactation

It is used in early pregnancy only when a specialist prescribes it; do not start or stop it on your own. It is not recommended while breastfeeding.

Precautions and Warnings

See your doctor about any unusual or heavy bleeding during treatment. Use with care if you have a history of depression, liver problems or porphyria. It does not prevent pregnancy, so use contraception if pregnancy is not wanted.

Overdose

Serious harm is unlikely. Too much may cause nausea, vomiting, dizziness or drowsiness. Seek medical advice.

Therapeutic Class

Progestogen (female sex hormone).

Storage

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