Estrogens


Generic Medicine Info
Indications and Dosage
Oral
Moderate to severe vasomotor symptoms associated with menopause
Adult: Initially, 0.3 mg per day, cyclically (either 3 weeks on and 1 week off or 25 days on and 5 days off) or daily, depending on patient’s condition. Subsequent dosage adjustment may be made based on patient response. Use lowest effective dose for the shortest duration.

Oral
Vaginal atrophy associated with menopause, Vulvar atrophy associated with menopause
Adult: Initially, 0.3 mg per day, cyclically (either 3 weeks on and 1 week off or 25 days on and 5 days off) or daily, depending on patient’s condition. Subsequent dosage adjustment may be made based on patient response. Use lowest effective dose for the shortest duration.

Oral
Hypogonadism-associated estrogen deficiency
Adult: 0.3 or 0.625 mg per day given cyclically (either 3 weeks on and 1 week off or 25 days on and 5 days off). Dose may be titrated in 6-12-month intervals; add progestin treatment to maintain bone mineral density once skeletal maturity is achieved.

Oral
Castration-associated estrogen deficiency, Primary ovarian failure-associated estrogen deficiency
Adult: 1.25 mg per day given cyclically (either 3 weeks on and 1 week off or 25 days on and 5 days off). Dose may be adjusted based on patient response. Use lowest effective dose for the shortest duration.

Oral
Prophylaxis of osteoporosis in postmenopausal women
Adult: Initially, 0.3 mg per day, cyclically (either 3 weeks on and 1 week off or 25 days on and 5 days off) or daily, depending on patient's condition. Subsequent dosage adjustment may be made based on patient response. Use lowest effective dose for the shortest duration.

Parenteral
Abnormal uterine bleeding
Adult: 25 mg via slow IV or IM inj, may repeat dose after 6-12 hours, if needed.

Vaginal
Kraurosis vulvae associated with menopause, Menopausal atrophic vaginitis
Adult: As 0.0625% cream: Initially, 0.5 g per day, given cyclically for 3 weeks of a 4-week cycle (21 days on, 7 days off). Adjust dose according to response (range: 0.5-2 g per day) Lowest effective dose should be used. Discontinue as promptly as possible.

Vaginal
Moderate dyspareunia associated with menopause, Severe dyspareunia associated with menopause
Adult: 0.5 g twice weekly as a continuous regimen (e.g. Monday and Thursday) or once daily cyclically (21 days on, 7 days off).
Incompatibility
Incompatible with ascorbic acid, protein hydrolysate, or any solution with acidic pH.
Contraindications
Hypersensitivity. Undiagnosed abnormal bleeding, previous or current venous thromboembolism (e.g. DVT, pulmonary embolism); active or recent arterial thromboembolic disease (e.g. MI), suspected or history of breast cancer, known or suspected estrogen-dependent tumours, untreated endometrial hyperplasia, porphyria, thrombophilic disorders (e.g. protein C, protein S or antithrombin deficiency). Hepatic impairment. Pregnancy.
Special Precautions
Patient with familial defects of lipoprotein metabolism, asthma, epilepsy, migraine, diabetes, porphyria, SLE, hereditary angioedema, hepatic haemangiomas, history of cholestatic jaundice associated with pregnancy or prior estrogen use; diseases that may be exacerbated by fluid retention (e.g. heart disease). Not intended for the prevention of CV disease or dementia. Renal impairment. Lactation.
Adverse Reactions
Significant: Endometriosis, retinal vascular thrombosis, increased HDL and triglycerides, decreased LDL; increased risk of gallbladder disease.
Cardiac disorders: Vasodilation.
Eye disorders: Intolerance to contact lenses.
Gastrointestinal disorders: Nausea, flatulence, abdominal pain.
General disorders and administration site conditions: Oedema, weakness, pain.
Infections and infestations: Vaginitis, vaginal candidiasis.
Investigations: Changes in weight.
Musculoskeletal and connective tissue disorders: Arthralgias, leg cramps, back pain.
Nervous system disorders: Dizziness, headache, migraine, anxiety.
Psychiatric disorders: Depression, change in libido, mood disturbances, insomnia.
Reproductive system and breast disorders: Abnormal uterine bleeding, vaginitis, leucorrhoea, vaginal haemorrhage, breast pain, tenderness, enlargement, discharge.
Respiratory, thoracic and mediastinal disorders: Pharyngitis, sinusitis.
Skin and subcutaneous tissue disorders: Alopecia, melasma, hirsutism, pruritus, rash.
Vascular disorders: Venous thrombosis, pulmonary embolism.
Potentially Fatal: Anaphylaxis, angioedema; increased risk of endometrial cancer.
Monitoring Parameters
Assess for risk of breast cancer and CV disease prior to therapy. Monitor blood pressure, serum triglycerides, TSH (in patients taking thyroid replacement). Perform age appropriate breast and pelvic exams during therapy.
Overdosage
Symptoms: Abdominal pain, dizziness, drowsiness, nausea, vomiting, fatigue, breast tenderness, withdrawal bleeding. Management: Symptomatic treatment.
Drug Interactions
Decreased plasma concentrations with CYP3A4 inducers (e.g. phenytoin, rifampicin). Increased plasma concentrations with CYP3A4 inhibitors (e.g. erythromycin, ritonavir).
Food Interaction
St. John’s wort may decrease estrogen plasma concentration.
Lab Interference
Interfere with tests for coagulation factors, lipids, binding proteins, and glucose tolerance.
Action
Description:
Mechanism of Action: Estrogens modulate pituitary secretion of gonadotropins, luteinising hormones and follicle-stimulating hormones through negative feedback mechanism, thus reducing elevated levels of these hormones in postmenopausal women during oestrogen replacement therapy
Pharmacokinetics:
Absorption: Well absorbed from the skin, mucous membranes, and gastrointestinal tract. Time to peak plasma concentration: 7 hours (total estrone).
Distribution: Widely distributed throughout the body with higher concentration in sex hormone target organs. Plasma protein binding: Binds to sex-hormone-binding globulin and albumin.
Metabolism: Metabolised in the liver by CYP3A4; undergoes enterohepatic recycling.
Excretion: Via urine (mainly as estriol, estradiol, estrone and conjugates). Elimination half-life: 27 hours (total estrone).
Storage
Tab/Vaginal cream: Store between 20-25°C. Solution for injection: Store at 2-8°C.
MIMS Class
Oestrogens, Progesterones & Related Synthetic Drugs
ATC Classification
G03C - ESTROGENS ; Used in estrogenic hormone preparations.
References
Anon. Estrogens (Conjugated/Equine, Systemic). Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 04/01/2019.

Anon. Estrogens (Conjugated/Equine, Topical). Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 04/01/2019.

Buckingham R (ed). Conjugated Oestrogens. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 04/01/2019.

Premarin for Injection (Pfizer). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 04/01/2019.

Premarin Tablet, Film Coated (Wyeth Pharmaceuticals LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 10/01/2019.

Premarin Vaginal Cream (Pfizer Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 04/01/2019.

Premarin Vaginal Cream In A Nonliquefying Base (Wyeth). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 04/01/2019.

Disclaimer: This information is independently developed by MIMS based on Estrogens from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2024 MIMS. All rights reserved. Powered by MIMS.com
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