Class: Estrogen Hormone
Dosage Forms. Tablet: 0.3 mg, 0.45 mg, 0.625 mg, 0.9 mg, 1.25 mg, 2.5 mg
Common FDA Label Indication, Dosing, and Titration.
1. Abnormal vasomotor function (menopause), atrophy of vagina or vulva, postmenopausal osteoporosis prophylaxis, female hypogonadism syndrome: 0.3 mg po daily, continuously or cyclically; adjust dose to individual response
2. Primary ovarian failure: 1.25 mg po daily cyclically (3 wk on, 1 wk off); adjust dose to individual response
Off-Label Uses. None
MOA. Estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. The primary source of estrogen in normally cycling adult women is the ovarian follicle. After menopause, most endogenous estrogen is produced by conversion of androstenedione to estrone by peripheral tissues. Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH), and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these gonadotropins seen in postmenopausal women.
Drug Characteristics: Conjugated Estrogens
Medication Safety Issues: Conjugated Estrogens
Drug Interactions: Conjugated Estrogens
Adverse Reactions: Conjugated Estrogens
Efficacy Monitoring Parameters. Resolution of clinical signs of abnormal bleeding or hot flashes or other symptoms, prevention of osteoporosis.
Toxicity Monitoring Parameters. Monitor BMD; conduct diagnostic evaluation to rule out malignancy in the event of persistent or recurring vaginal bleeding.
Key Patient Counseling Points. Discuss potential long-term adverse effects of hormone therapy including myocardial infarction, stroke, deep vein thrombosis, pulmonary embolism, and breast cancer.
Clinical Pearls. Injectable and vaginal cream is also available for other indications requiring estrogen replacement therapy. Combination of estrogens and progestins should not be used for the prevention of cardiovascular disease. Increased risk (over placebo) of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis has been shown in postmenopausal women. Because of these risks, estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman. In postmenopausal women with a uterus, a progestin (eg, medroxyprogesterone) should be added to estrogen to reduce the risk of endometrial cancer. Increased incidence of dementia was observed in women ≥65 y of age taking estrogens.