estradiol: clinical use

Prescribing considerations

• Confirm the indication and assess individual benefits and risks before starting or restarting systemic HRT; review periodically.
• People with an intact uterus usually require adequate progestogen protection against endometrial hyperplasia and cancer.
• Investigate unexplained genital bleeding. Assess thromboembolic, cardiovascular, breast, endometrial and liver history and risk factors.
• Estradiol HRT is not contraceptive. Discuss contraception where pregnancy remains possible.
• Closer supervision may be appropriate with fibroids, endometriosis, hypertension, diabetes, migraine, epilepsy, gallstones, systemic lupus erythematosus or asthma.

Contraindications and cautions

• Known, previous or suspected breast cancer
• Known or suspected oestrogen-dependent malignancy
• Undiagnosed genital bleeding or untreated endometrial hyperplasia
• Previous or current venous thromboembolism or a known thrombophilic disorder
• Active or recent arterial thromboembolic disease
• Acute liver disease, or previous liver disease while function remains abnormal
• Hypersensitivity to the product or porphyria

Monitoring

• Record relevant personal and family history before treatment; direct examination according to history, contraindications and warnings.
• Review symptom control, adverse effects, bleeding pattern and the continuing benefit-risk balance periodically.
• Advise reporting breast changes and maintain appropriate routine breast screening.
• Assess persistent, heavy or newly changed vaginal bleeding.
• Stop and assess if jaundice, deteriorating liver function, a significant blood-pressure rise, new migraine-type headache, pregnancy or a thromboembolic event occurs.

Clinical pharmacology

Synthetic 17β-estradiol is chemically and biologically identical to endogenous estradiol. Transdermal absorption supplies systemic oestrogen while largely avoiding hepatic first-pass metabolism; estradiol is converted mainly to estrone and conjugated metabolites.

Formulation and product differences

• Evorel Gel is licensed for postmenopausal oestrogen-deficiency symptoms and requires precautions to prevent skin-to-skin transfer.
• Evorel patches are licensed for peri- and postmenopausal oestrogen-deficiency symptoms; selected presentations also have an osteoporosis-prevention indication.
• Patches remain attached during normal bathing or showering but may cause local adhesive-site reactions. Gel must dry before covering, and the application site must be protected from contact with others.

Gel

Route: Cutaneous

Strengths: 750 micrograms/actuation