Estring
ESTRING®
(estradiol) Vaginal Ring 2 mg
ESTROGENS INCREASE THE RISK OF ENDOMETRIAL CANCER
Close clinical surveillance of all women taking estrogens is important. Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding. There is no evidence that the use of “natural" estrogens results in a different endometrial risk profile than synthetic estrogens at equivalent estrogen doses. (See WARNINGS, Malignant neoplasms, Endometrial cancer.)
CARDIOVASCULAR AND OTHER RISKS
Estrogens with and without progestins should not be used for the prevention of cardiovascular disease or dementia. (See Clinical Studies and WARNINGS, Cardiovascular disorders and Dementia.).
The estrogen alone substudy of the Women's Health Initiative (WHI) reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 6.8 years and 7.1 years, respectively, of treatment with oral conjugated estrogens (CE 0.625 mg) alone per day relative to placebo. (See Clinical Studies and WARNINGS, Cardiovascular disorders.)
The estrogen plus progestin substudy of the WHI reported increased risks of myocardial infarction, stroke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with oral conjugated estrogens (CE 0.625 mg) combined with medroxyprogesterone acetate (MPA 2.5 mg) per day relative to placebo (See Clinical Studies and WARNINGS, Cardiovascular disorders and Malignant neoplasms, Breast cancer).
The Women's Health Initiative Memory Study (WHIMS) a substudy of WHI,, reported increased risk of developing probable dementia in postmenopausal woman 65 years of age or older during 5.2 years of treatment with CE 0.625 mg alone and during 4 years of treatment with CE 0.625 mg combined with MPA 2.5 mg relative to placebo. It is unknown whether this finding applies to younger postmenopausal women. (See Clinical Studies, WARNINGS, Dementia and PRECAUTIONS, Geriatric Use)
Other doses of conjugated estrogens and medroxyprogesterone acetate, other combinations and dosage forms of estrogens and progestins were not studied in the WHI clinical trials and, in the absence of comparable data, these risks should be assumed to be similar. 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.
DRUG DESCRIPTION
ESTRING® (estradiol vaginal ring) is a slightly opaque ring with a whitish core containing a drug reservoir of 2 mg estradiol. Estradiol, silicone polymers and barium sulfate are combined to form the ring. When placed in the vagina, ESTRING releases estradiol, approximately 7.5 µg/24 hours, in a consistent stable manner over 90 days. ESTRING has the following dimensions: outer diameter 55 mm; cross-sectional diameter 9 mm; core diameter 2 mm. One ESTRING should be inserted into the upper third of the vaginal vault, to be worn continuously for three months. Estradiol is chemically described as estra-1,3,5(10)-triene-3,17β-diol. The molecular formula of estradiol is C18H24O2 and the structural formula is:
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The molecular weight of estradiol is 272.39.
Generic Name: Estradiol Vaginal Ring
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