BMA Concise Guide to Medicine & Drugs

Ethinylestradiol

Used in the following combined preparations Co-cyprindiol, combined oral contraceptives (e.g. Brevinor, Femodene, Loestrin, Marvelon, Mercilon, Microgynon 30, Norimin, Ovranette, Ovysmen, Yasmin), Dianette

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Drug group Female sex hormone and oral contraceptive

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Ethinylestradiol is a synthetic oestrogen similar to estradiol, a natural female sex hormone. It is widely used in oral contraceptives in combination with a synthetic progestogen. These can also be used to treat an irregular menstrual cycle and conditions in women due to high levels of androgen (male sex hormones), such as polycystic ovary syndrome and hirsutism; they may also be used as HRT for the short-term relief of menopausal symptoms. Ethinylestradiol may also be used to treat hypogonadism (late or absent sexual development) in women and, more rarely, osteoporosis, prostate cancer and, in combination with cyproterone, acne in women.

Women taking an oral contraceptive containing ethinylestradiol have an increased risk of venous thrombosis. This risk is greater in overweight women and smokers.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets.

Frequency and timing of doses Once daily. Often at certain times of the menstrual cycle.

Adult dosage range Menopausal symptoms 10–20mcg daily. Hormone deficiency 10–50mcg daily. Combined contraceptive pills 20–40mcg daily, depending on preparation. Acne 35mcg daily. Prostate cancer 0.15–1.5mg daily.

Onset of effect 10–20 days. Contraceptive protection is effective after 7 days in most cases.

Duration of action 1–2 days.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 4 hours, take a single dose now and skip the next. If you are taking the drug for contraceptive purposes, see What to do if you miss a pill.

Stopping the drug Do not stop the drug without consulting your doctor. Contraceptive protection is lost unless an alternative is used.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

The most common adverse effects of ethinylestradiol include nausea, vomiting, breast swelling or tenderness, weight gain, fluid retention, and bleeding between periods. They generally diminish with time but discuss with your doctor if they are severe or if you experience headaches or depression. Sudden, sharp pain in the chest, groin, or legs may indicate a blood clot. If you experience such pain or develop sudden breathlessness, jaundice or itching, stop taking the drug and seek urgent medical attention. Long-term use is not advised because it carries an increased risk of various disorders (see Prolonged use).

INTERACTIONS

Tobacco smoking This increases the risk of serious adverse effects on the heart and circulation with ethinylestradiol.

Rifampicin and anticonvulsants These drugs significantly reduce the effectiveness of oral contraceptives containing ethinylestradiol.

Antihypertensive drugs, anticoagulants, and diuretics Ethinylestradiol may reduce the effectiveness of these drugs.

Antibiotics and St John’s wort may reduce the effectiveness of oral contraceptives containing ethinylestradiol.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have heart failure or high blood pressure.

· You have had venous thrombosis or a stroke.

· You have a long-term liver or kidney problems.

· You have had breast or endometrial cancer.

· You have diabetes, porphyria, or sickle cell anaemia.

· You are a smoker.

· You suffer from migraine or epilepsy.

· You are taking other medicines.

Pregnancy Not prescribed. High doses may adversely affect the baby. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk; it may also inhibit milk flow. Discuss with your doctor.

Infants and children Not usually prescribed.

Over 60 No special problems.

Driving and hazardous work No known problems.

Alcohol No known problems.

Surgery and general anaesthetics Ethinylestradiol may need to be stopped several weeks before you have major surgery. Discuss this with your doctor.

PROLONGED USE

As part of HRT, ethinylestradiol is usually only advised for short-term use around the menopause and is not normally recommended for long-term use or for treatment of osteoporosis. Long-term use increases the risk of breast cancer, venous thrombosis, heart attack, and stroke.

Monitoring Physical examinations and blood pressure checks may be performed.