Indications
Cyproterone Acetate is an anti-androgen and progestogen. In low doses it is combined with Ethinylestradiol in a pill used for women with moderate to severe acne and/or excess body or facial hair (hirsutism) caused by sensitivity to male hormones, often in polycystic ovary syndrome, when other treatments have not worked; this pill also prevents pregnancy. In higher doses on its own it is used to treat prostate cancer and, under specialist care, some other conditions such as severe hypersexuality in men.
How It Works
Cyproterone blocks androgen (male hormone) receptors so testosterone cannot act on the skin, hair follicles and prostate. It also reduces the release of hormones from the pituitary gland, lowering testosterone production. In women this reduces oil production in the skin and excess hair growth; together with Ethinylestradiol it also stops ovulation.
Dosage and Administration
This is a hormone medicine, so take it exactly as prescribed. The combined pill for women is usually taken once a day at the same time for 21 days, followed by a 7-day break, as directed on the pack; improvement in acne and hair takes several months. Higher-dose tablets for men are used only on a specialist’s prescription. Do not use the combined pill together with another hormonal contraceptive.
Interactions
- Enzyme-inducing medicines such as Rifampicin, Carbamazepine, Phenytoin, Phenobarbitone, some HIV medicines and St John’s wort: reduce its effect and contraceptive protection.
- Ketoconazole, Itraconazole, Clarithromycin and Ritonavir: may increase its levels.
- Medicines for diabetes: needs may change.
- Lamotrigine: levels may fall with the combined pill.
- Other hormonal contraceptives: do not use together.
Contraindications
Do not use if you have or have had a blood clot in a vein or artery, stroke, heart attack, high risk of clots, migraine with aura, severe high blood pressure, diabetes with blood vessel damage, liver disease or liver tumour, a meningioma (a usually benign brain tumour) or history of one, hormone-sensitive cancer (for the combined pill), unexplained vaginal bleeding, pregnancy, breastfeeding, or allergy to any ingredient. Not for use in children or for women as contraception alone.
Side Effects
- Nausea, headache, breast tenderness, weight changes.
- Mood changes or depression, reduced sex drive.
- Irregular bleeding or spotting.
- In men on higher doses: tiredness, breast enlargement, reduced sperm production and fertility, erection problems.
- Rarely: liver damage (mainly with high doses), blood clots, meningioma with long-term high-dose use.
Get urgent medical help for pain or swelling in one leg, sudden chest pain or breathlessness, sudden weakness or numbness of the face or limbs, severe headache or vision changes, yellow skin or eyes, dark urine or severe stomach pain, or thoughts of self-harm.
Pregnancy and Lactation
Must not be used in pregnancy, as it can affect the development of a male baby. Stop and see your doctor if you think you are pregnant. Not to be used during breastfeeding.
Precautions and Warnings
The combined pill carries a higher risk of blood clots than some other contraceptive pills, especially in the first year, in smokers, people over 35, those who are overweight or immobile. Stop it about 4 weeks before major planned surgery as advised. Once skin and hair symptoms are controlled, the doctor will review whether it should continue. Liver tests and blood sugar may be checked. Tell your doctor about depression, diabetes, high blood pressure or any history of clots in your family.
Overdose
Overdose may cause nausea, vomiting and vaginal bleeding in women. Serious effects are unlikely, but seek medical advice.
Therapeutic Class
Anti-androgen and progestogen (hormonal medicine).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.