oestrogens, conjugated: clinical use

Prescribing considerations

• Confirm that symptoms adversely affect quality of life and reassess the individual benefit-risk balance periodically.
• An intact uterus generally requires adequate progestogenic endometrial protection.
• Assess personal and family history, unexplained bleeding, cancer and thromboembolic, cardiovascular, hepatic and metabolic risk.
• Use particular caution with fibroids, endometriosis, migraine, hypertension, diabetes, gallstones, epilepsy, asthma, systemic lupus erythematosus and hypertriglyceridaemia.
• Consider perioperative thromboembolic risk when major surgery or prolonged immobilisation is expected.

Contraindications and cautions

• Known, suspected or previous breast cancer
• Known or suspected oestrogen-dependent malignancy
• Unexplained genital bleeding or untreated endometrial hyperplasia
• Previous or current venous thromboembolism or known thrombophilia
• Active or recent arterial thromboembolic disease
• Active liver disease, or previous liver disease with persistently abnormal function
• Porphyria or hypersensitivity to the product

Monitoring

• Review symptom response, adverse effects and continuing benefit-risk balance.
• Investigate persistent, heavy or newly occurring unscheduled bleeding.
• Support routine breast awareness and appropriate screening.
• Monitor blood pressure and relevant hepatic, metabolic, triglyceride or thyroid measures when clinically indicated.
• Guide treatment primarily by clinical response rather than serum oestradiol or gonadotrophin concentrations.

Clinical pharmacology

Oral conjugated oestrogens are absorbed after slow release from the coated formulation. Their components bind nuclear oestrogen receptors, undergo mainly hepatic metabolism and enterohepatic recirculation, and are excreted in urine as glucuronide and sulfate conjugates.

Formulation and product differences

• The selected preparation is a systemic oral sugar-coated tablet that releases conjugated oestrogens slowly over several hours.
• It contains lactose and sucrose, which matter in specific hereditary carbohydrate-intolerance disorders.
• Conjugated oestrogens are a mixture of naturally occurring oestrogen compounds rather than a single estradiol preparation.