Formulary
Conjugated oestrogens: Indications, Dosing, Side Effects and Interactions
Conjugated oestrogens clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 4 min read
Conjugated oestrogens: Indications, Dosing, Side Effects and Interactions
Conjugated oestrogens clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Menopausal symptoms**
- **Adult** (By Mouth): 0.3-1.25 mg daily continuously; with cyclical progestogen for 12-14 days of each cycle in women with a uterus.
**Postmenopausal osteoporosis prophylaxis**
- **Adult** (By Mouth): 0.625-1.25 mg daily continuously; with cyclical progestogen for 12-14 days of each cycle in women with a uterus.
Cautions
Acute porphyrias ; diabetes (increased risk of heart disease); factors predisposing to thromboembolism; history of breast nodules (closely monitor breast status-risk of breast cancer); history of endometrial hyperplasia; history of fibrocystic disease (closely monitor breast status-risk of breast cancer); hypophyseal tumours; increased risk of gall-bladder disease reported; migraine; migraine-like headaches; presence of antiphospholipid antibodies (increased risk of thrombotic events); risk factors for oestrogen-dependent tumours (e.g. breast cancer in first-degree relative); risk of breast cancer; symptoms of endometriosis may be exacerbated; uterine fibroids may increase in size Cautions, further information Risk of breast cancer HRT use is associated with an increased risk of breast cancer-see Important safety information . Radiological detection of breast cancer can be made more difficult as mammographic density can increase with HRT use. Risk of endometrial cancer The increased risk of endometrial cancer depends on the dose and duration of oestrogen-only HRT. In women with a uterus, the addition of a progestogen cyclically (for at least 10 days per 28-day cycle) reduces the additional risk of endometrial cancer; this additional risk is eliminated if a progestogen is given continuously. However, this should be weighed against the increased risk of breast cancer. Risk of ovarian cancer Long-term use of combined HRT or oestrogen-only HRT is associated with a small increased risk of ovarian cancer. This excess risk disappears within a few years of stopping. Risk of venous thromboembolism Women using combined or oestrogen-only HRT are at an increased risk of deep vein thrombosis and of pulmonary embolism especially in the first year of use. In women who have predisposing factors (such as a personal or family history of deep vein thrombosis or pulmonary embolism, severe varicose veins, obesity, trauma, or prolonged bed-rest) it is prudent to review the need for HRT, as in some cases the risks of HRT may exceed the benefits. Travel involving prolonged immobility further increases the risk of deep vein thrombosis. Risk of stroke Risk of stroke increases with age, therefore older women have a greater absolute risk of stroke. Combined HRT or oestrogen-only HRT increases the risk of stroke. Risk of coronary heart disease HRT does not prevent coronary heart disease and should not be prescribed for this purpose. There is an increased risk of coronary heart disease in women who start combined HRT more than 10 years after menopause. Although very little information is available on the risk of coronary heart disease in younger women who start HRT close to the menopause, studies suggest a lower relative risk compared with older women.
Contraindications
Active arterial thromboembolic disease (e.g. angina or myocardial infarction); history of breast cancer; history of venous thromboembolism; liver disease (where liver function tests have failed to return to normal); oestrogen-dependent cancer; recent arterial thromboembolic disease (e.g. angina or myocardial infarction); thrombophilic disorder; undiagnosed vaginal bleeding; untreated endometrial hyperplasia
Side effects
Common or very common Alopecia; arthralgia; breast abnormalities; depression; leg cramps; menstrual cycle irregularities; vaginal discharge; weight changes Uncommon Anxiety; cervical abnormalities; contact lens intolerance; dizziness; embolism and thrombosis; gallbladder disorder; gastrointestinal discomfort; headaches; hirsutism; libido disorder; mood altered; nausea; oedema; skin reactions; vulvovaginal candidiasis Rare or very rare Angioedema; asthma exacerbated; cerebrovascular insufficiency; chorea exacerbated; colitis ischaemic; epilepsy exacerbated; galactorrhoea; glucose tolerance impaired; hypocalcaemia; jaundice cholestatic; myocardial infarction; neoplasms; pancreatitis; pelvic pain; vomiting Frequency not known Endometrial hyperplasia; erythema nodosum Side-effects, further information Cyclical HRT (where a progestogen is taken for 12-14 days of each 28-day oestrogen treatment cycle) usually results in regular withdrawal bleeding towards the end of the progestogen. Continuous combined HRT commonly produces irregular breakthrough bleeding in the first 4-6 months of treatment. Bleeding beyond 6 months or after a spell of amenorrhoea requires further investigation to exclude serious gynaecological pathology.
Pregnancy
Manufacturer advises avoid-not indicated during pregnancy.
Breast feeding
Avoid until weaning or for 6 months after birth (adverse effects on lactation).
Hepatic impairment
Manufacturer advises caution; avoid in acute or active disease.
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
FormularyBrowse all drugs
Search 1,850+ drug profiles.
Study Conjugated oestrogens in the MedNext app
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary

