ESTRADIOL
(ess-tra-dye'ole)
Alora, Climara, Esclim, Estrace, Estraderm, Estrasorb, EstroGel, FemPatch, Menorest, Menostar, Vivelle, Vivelle DOT, Estring, Vagifem
ESTRADIOL ACETATE
Femring, Femtrace
ESTRADIOL CYPIONATE
Depo-Estradiol Cypionate, depGynogen, Depogen, Dura-Estrin, Estro-Cyp, Estroject-LA, and others
ESTRADIOL VALERATE
Delestrogen, Dioval, Duragen-10, Estraval, Femogex , Gynogen LA, Valergen
Classifications: hormones & synthetic substitutes; estrogens
Pregnancy Category: X

Availability

Estradiol 0.025 mg, 0.0375 mg, 0.05 mg, 0.06 mg, 0.075 mg, 0.1 mg patch; 14 mcg/24 h transdermal patch; 0.5 mg, 1 mg, 2 mg tablets; 25 mcg vaginal tablets, 2 mg vaginal ring, 0.1 mg vaginal cream; 2.5 mg/g topical emulsion; 0.06% topical gel;

Cypionate 5 mg/mL injection;

Valerate 10 mg/mL, 20 mg/mL, 40 mg/mL injection;

Acetate 0.45 mg, 0.9 mg, 1.8 mg tablets; 0.05 mg/d, 0.1 mg/d vaginal insert

Actions

Natural or synthetic steroid hormone secreted principally by the ovarian follicles, and also by the adrenals, corpus luteum, placenta, and testes. Estrogen binds to a specific intracellular receptor, forming a complex that stimulates synthesis of proteins responsible for estrogenic effects. Promotes endometrial lining development, but prolonged exposure leads to abnormal endometrial hyperplasia, a condition usually associated with an abnormal bleeding pattern. Conversely, estrogen-stimulated endometrium suddenly deprived of estrogen may bleed within 48–72 h.

Therapeutic Effects

In general, estradiol (estrogens) effects simulate those produced by the endogenous hormone. May mask onset of climacteric.

Uses

Natural or surgical menopausal symptoms, kraurosis vulvae, atrophic vaginitis, primary ovarian failure, female hypogonadism, castration. Used adjunctively with diet, calcium, and physical therapy to prevent and treat postmenopausal osteoporosis; also for palliation in advanced prostatic carcinoma and inoperable metastatic breast cancer in women at least 5 y after menopause. Combined with progestins in many oral contraceptive formulations.

Contraindications

Known or suspected pregnancy (category X); estrogenic-dependent neoplasms, breast cancer (except in selected patients being treated for metastatic disease). History of thromboembolic disorders; active arterial thrombosis or thrombophlebitis; undiagnosed abnormal genital bleeding; history of cholestatic disease; thyroid dysfunction; blood dyscrasias.

Cautious Use

Adolescents with incomplete bone growth; endometriosis; hypertension, cardiac insufficiency; diseases of calcium and phosphate metabolism (metabolic bone disease); cerebrovascular disease; mental depression; benign breast disease, family history of breast or genital tract neoplasm; diabetes mellitus; gall bladder disease; preexisting leiomyoma, abnormal mammogram, history of idiopathic jaundice of pregnancy; varicosities; asthma; epilepsy; migraine headaches; liver or kidney dysfunction; jaundice, acute intermittent porphyria, pyridoxine deficiency; lactation.

Route & Dosage

Menopause, Atrophic Vaginitis, Kraurosis Vulvae, Female Hypogonadism, Female Castration, Primary Ovarian Failure
Adult: PO 0.45–2 mg/d in a cyclic regimen Topical 2–4 g vaginal cream intravaginally once/d for 1–2 wk, then 1–2 g/d for 1–2 wk, then 1 g 1–3 times/wk; Transdermal patch Estraderm twice weekly; Climara, FemPatch, Menostar qwk in a cyclic regimen; Estrasorb Apply 1 packet to the left thigh and calf and 1 packet to the right thigh and calf once daily in the morning; EstroGel Apply 1.25 g (one-half applicatorful) to one arm every day (usually in the morning). IM Cypionate 1–5 mg once q3–4wk; Valerate 10–25 mg once q4wk; Acetate Insert 1 vaginal ring into the upper third of the vaginal vault. Keep in place continuously for 3 mo, then remove.

Metastatic Breast Cancer
Adult: PO 10 mg t.i.d.

Prostatic Cancer
Adult: PO 1–2 mg t.i.d. IM Valerate 30 mg once q1–2wk

Postpartum Breast Engorgement
Adult: IM Valerate 10–25 mg at end of first stage of labor

Administration

Oral
Intravaginal
Topical
Transdermal
Intramuscular

Adverse Effects (1%)

CNS: Headache, migraine, dizziness, mental depression, chorea, convulsions, increased risk of dementia. CV: Thromboembolic disorders, stroke, CAD, hypertension. Special Senses: Intolerance to contact lenses, worsening of myopia or astigmatism, scotomas. GI: Nausea, vomiting, anorexia, increased appetite, diarrhea, abdominal cramps or pain, constipation, bloating, colitis, acute pancreatitis, cholestatic jaundice, benign hepatoadenoma. Urogenital: Mastodynia, breast secretion, spotting, changes in menstrual flow, dysmenorrhea, amenorrhea, cervical erosion, altered cervical secretions, premenstrual-like syndrome, vaginal candidiasis, endometrial cystic hyperplasia, reactivation of endometriosis, increased size of preexisting fibromyomas, cystitis-like syndrome, hemolytic uremic syndrome, change in libido; in men: gynecomastia, testicular atrophy, feminization, impotence (reversible). Metabolic: Reduced carbohydrate tolerance, hyperglycemia, hypercalcemia, folic acid deficiency, fluid retention. Skin: Dermatitis, pruritus, seborrhea, oily skin, acne; photosensitivity, chloasma, loss of scalp hair, hirsutism. Body as a Whole: Pain and postinjection flare at injection site; sterile abscess; leg cramps, weight changes. Hematologic: Acute intermittent porphyria.

Diagnostic Test Interference

Estradiol reduces response of metyrapone test and excretion of pregnanediol. Increases: BSP retention, norepinephrine-induced platelet aggregability, hydrocortisone, PBI, T4, sodium, thyroxine-binding globulin (TBG), prothrombin and factors VII, VIII, IX, and X; serum triglyceride, and phospholipid concentrations, renin substrate. Decreases: antithrombin III, pyridoxine and serum folate concentrations, serum cholesterol, values for the T3 resin uptake test, glucose tolerance. May cause false-positive test for LE cells or antinuclear antibodies (ANA).

Interactions

Drug: barbiturates, phenytoin, rifampin decrease estrogen effect by increasing its metabolism; oral anticoagulants may decrease hypoprothrombinemic effects; interfere with effects of bromocriptine; may increase levels and toxicity of cyclosporine, tricyclic antidepressants, theophylline; decrease effectiveness of clofibrate.

Pharmacokinetics

Absorption: Rapid absorption from GI tract; readily absorbed through skin and mucous membranes; slow absorption from IM injections. Distribution: Distributed throughout body tissues, especially in adipose tissue; crosses placenta. Metabolism: Metabolized primarily in liver. Elimination: Excreted in urine; excreted in breast milk.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug