Overview
CLINICAL PHARMACOLOGY Estrogens Estrogens are important in the development and maintenance of the female reproductive system and secondary sex characteristics. They promote growth and development of the vagina, uterus, and fallopian tubes, and enlargement of the breasts. Indirectly, they contribute to the shaping of the skeleton, maintenance of tone and elasticity of urogenital structures,...
Mechanism of Action
CLINICAL PHARMACOLOGY Estrogens Estrogens are important in the development and maintenance of the female reproductive system and secondary sex characteristics. They promote growth and development of the vagina, uterus, and fallopian tubes, and enlargement of the breasts. Indirectly, they contribute to the shaping of the skeleton, maintenance of tone and elasticity of urogenital structures, changes in the epiphyses of the long bones that allow for the pubertal growth spurt and its termination, growth of axillary and pubic hair, and pigmentation of the nipples and genitals. Decline of estrogenic activity at the end of the menstrual cycle can bring on menstruation, although the cessation of progesterone secretion is the most important factor in the mature ovulatory cycle.
Indications
- INDICATIONS AND USAGE ESTERIFIED ESTROGENS AND METHYLTESTOSTERONE FULL STRENGTH and ESTERIFIED ESTROGENS AND METHYLTESTOSTERONE HALF STRENGTH are indicated in the treatment of: Moderate to severe vasomotor symptoms associated with the menopause in those patients not improved by estrogens alone. (There is no evidence that estrogens are effective for nervous symptoms or depression without associated vasomotor symptoms, and they should not be used to treat such conditions.
Common Doses
- Refer to label
Dosage
DOSAGE AND ADMINISTRATION 1. Given cyclically for short-term use only: For treatment of moderate to severe vasomotor symptoms associated with the menopause in patients not improved by estrogen alone. The lowest dose that will control symptoms should be chosen and medication should be discontinued as promptly as possible. Administration should be cyclic (e.g., three weeks on and one week off). Attempts to discontinue or taper medication should be made at three to six month intervals.
Black Box Warning
WARNINGS 1. ESTROGENS HAVE BEEN REPORTED TO INCREASE THE RISK OF ENDOMETRIAL CARCINOMA Three independent case control studies have reported an increased risk of endometrial cancer in postmenopausal women exposed to exogenous estrogens for prolonged periods. 1-3 This risk was independent of the other known risk factors for endometrial cancer. These studies are further supported by the finding that incidence rates of endometrial cancer have increased sharply since 1969 in eight different areas of the United States with population-based cancer reporting systems, an increase which may be related...
Contraindications
- CONTRAINDICATIONS Estrogens should not be used in women with any of the following conditions: 1. Known or suspected cancer of the breast except in appropriately selected patients being treated for metastatic disease. 2. Known or suspected estrogen-dependent neoplasia. 3. Known or suspected pregnancy (See Boxed Warning ). 4. Undiagnosed abnormal genital bleeding. 5. Active thrombophlebitis or thromboembolic disorders. 6. A past history of thrombophlebitis, thrombosis, or thromboembolic disorders associated with previous estrogen use (except when in treatment of breast malignancy).
Side Effects
- ADVERSE REACTIONS Associated with Estrogens (See Warnings regarding induction of neoplasia, adverse effects on the fetus, increased incidence of gallbladder disease, and adverse effects similar to those of oral contraceptives, including thromboembolism). The following additional adverse reactions have been reported with estrogenic therapy, including oral contraceptives: Genitourinary system. Breakthrough bleeding, spotting, change in menstrual flow. Dysmenorrhea. Premenstrual-like syndrome. Amenorrhea during and after treatment. Increase in size of uterine fibromyomata. Vaginal candidiasis.
Interactions
- D. Drug Interactions 1. Anticoagulants C-17 substituted derivatives of testosterone, such as methandrostenolone, have been reported to decrease the anticoagulant requirements of patients receiving oral anticoagulants. Patients receiving oral anticoagulant therapy require close monitoring, especially when androgens are started or stopped. 2. Oxyphenbutazone . Concurrent administration of oxyphenbutazone and androgens may result in elevated serum levels of oxyphenbutazone. 3. Insulin . In diabetic patients the metabolic effects of androgens may decrease blood glucose and insulin requirements.