ESTRING (estradiol)

Pharmacokinetics

AbsorptionEstrogens used in therapeutics are well absorbed through the skin, mucous membranes, and the gastrointestinal (GI) tract. The vaginal delivery of estrogens circumvents first-pass metabolism. In a Phase I study of 14 postmenopausal women, the insertion of ESTRING (estradiol vaginal system) rapidly increased serum estradiol (E 2 ) levels. The time to attain peak serum estradiol levels (T max ) was 0.5 to 1 hour. Peak serum estradiol concentrations post-initial burst dec...

CLINICAL STUDIES Effects on Vulvar and Vaginal Atrophy Two controlled studies have demonstrated the efficacy of ESTRING (estradiol vaginal system) in the treatment of postmenopausal urogenital symptoms due to estrogen deficiency. In a U.S. study where ESTRING was compared with conjugated estrogens vaginal cream, no difference in efficacy between the treatment groups was found with respect to improvement in the physician's global assessment of vaginal symptoms (83 percent and 82 percent of patients receiving ESTRING and cream, respectively) and in the patient's global assessment of vaginal symp...

ADVERSE REACTIONS See WARNINGS and PRECAUTIONS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In the two ESTRING controlled studies, discontinuation of treatment due to an adverse event was required by 5.4 percent of patients receiving ESTRING and 3.9 percent of patients receiving c...

CONTRAINDICATIONS ESTRING is contraindicated in women with any of the following conditions: 1. Abnormal genital bleeding with unknown etiology. 2. Known or suspected estrogen-dependent neoplasia. 3. Active DVT, PE, or a history of these conditions. 4. Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions. 5. Known anaphylactic reaction or angioedema ...