Estradiol
Common Brand Names: See Below
Generic available in some formulations
Common Dosage Forms:
Topical Patients (Vivelle-Dot, Alora, Climara): Available to deliver 0.025 mg, 0.05 mg, 0.075 mg, and 0.1 mg each day
Tablets (Estrace): 0.5 mg, 1 mg, 2 mg
Divigel: 0.25 mg, 0.5 mg, 1 mg per packet
Femring Vaginal Insert: 5 mcg and 10 mcg delivered over 24 hours
Estring Vaginal Insert: 7.5 mcg delivered over 24 hours
Vagifem Suppository: 10 mcg
Cream (Estrace): 0.01%
*Not all forms are covered here, including injectable forms.
FDA Indications/Dosages:
Treatment of moderate to severe vasomotor symptoms associated with menopause, treatment of vulvar and vaginal atrophy, and treatment of hypoestrogenism due to hypogonadism, castration, or primary ovarian failure: Oral: 0.5-2 mg once daily. Vivelle-Dot, Alora: One patch applied twice weekly. Climara: One patch applied once weekly. Femring, Estring: Inserted vaginally once every 3 months. Vagifem, Estrace cream: Inserted vaginally from once daily to once weekly. Divigel: One packet applied daily.
Pharmacology/Pharmacokinetics: Estrogens promote growth and development of the vagina, uterus, and fallopian tube, and enlargement of the breasts. They are also involved in the process of menstruation. Estradiol is the more potent of the estrogens with estrone and estriol being less potent. In premenopausal women the ovarian follicle produces estradiol. In postmenopausal women the primary source of estrogen is through conversion of androstenedione to estrone. Transdermal applied estradiol avoids the first-pass metabolism of orally-administered estradiol to estrone. Estradiol has a half-life of 1 hour with reapplication estrogen levels being attained within 24 hours of removing a transdermal system.
Drug Interactions: Barbiturates, St. John’s Wort, carbamazepine, and rifampin may increase the metabolism of estrogens. Erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir, and grapefruit juice may decrease the metabolism of estrogens.
Contraindications/Precautions: Contraindicated in women with cancer of the breast, estrogen-dependant neoplasia, undiagnosed genital bleeding, active thromboembolic disorders or a past history of thromboembolic disorders, or during pregnancy. ESTROGEN-ALONE THERAPY INCREASES THE RISK OF STROKE, DEEP VEIN THROMBOSIS, ENDOMETRIAL CANCER, AND IN WOMEN OVER 65 YEARS OF AGE, PROBABLE DEMENTIA. Use with extreme caution in women with a family history of breast cancer or who have breast nodules, fibrocystic disease, or abnormal mammograms. Breast examinations should be performed periodically. Estrogens have been shown to increase the risk of gallbladder disease, thromboembolic disease, hepatic adenoma, high blood pressure, decreased glucose tolerance, and hypercalcemia. Use with caution in patients with a history of depression, when nursing, with liver, cardiac, or kidney dysfunction, and in those with epilepsy. Pregnancy Category X.
Adverse Effects: Irritation of application site, EDEMA, THROMBOEMBOLIC disorders, breast tenderness, disturbances in menstruation, and depression.
Patient Consultation:
Discuss the uses and dangers of estrogen therapy (package insert).
Do not take during pregnancy.
Closely follow cyclic administration.
Water will not affect patches.
Avoid application sites that are oily, damaged, irritated, or wet.
Store in a cool, dry place away from sunlight and children.
If a dose is missed, apply it as soon as possible. Do not double doses.
Contact a physician if the above side effects are severe or persistent.
