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Understanding the WHI estrogen alone substudy can help you feel confident about your treatment decision

The Women's Health Initiative (WHI) estrogen alone substudy evaluated outcomes in 10,739 generally healthy postmenopausal women without a uterus, taking either PREMARIN (conjugated estrogens)
0.625 mg or placebo5

Clinical outcomes from the WHI estrogen alone substudy

Study Descriptions >

  • Study did not include lower PREMARIN (conjugated estrogens) doses: 0.3 mg and 0.45 mg5
  • VTE comprises deep vein thrombosis (DVT) and pulmonary embolism (PE)

Risk calculations provide a basis by which health care providers and patients can weigh the pros and cons of initiating or continuing therapy. Absolute risk (shown) is the difference between the incidence rates and the exposed and unexposed groups. Therefore, the absolute risk quantifies the effect of an exposure on a population basis, providing a measure of its public health impact.12

Click to view age stratification results

Important Safety Information

There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens. Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding.

The Women's Health Initiative (WHI) estrogen alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women during 7.1 years of treatment with daily oral conjugated estrogens (CE) alone, relative to placebo. The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism, stroke, and myocardial infarction in postmenopausal women during 5.6 years of treatment with daily oral CE combined with medroxyprogesterone acetate (MPA), relative to placebo.

The WHI Memory Study (WHIMS) estrogen alone study reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 5.2 years of treatment with daily CE alone, relative to placebo. The WHIMS estrogen plus progestin study reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with daily CE combined with MPA, relative to placebo. It is unknown whether these findings apply to younger postmenopausal women.

The WHI estrogen plus progestin substudy demonstrated an increased risk of invasive breast cancer.

Estrogens with or without progestins should not be used for the prevention of cardiovascular disease or dementia.

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.

PREMARIN should not be used in women with any of the following conditions: undiagnosed abnormal genital bleeding; known, suspected, or a history of breast cancer; known or suspected estrogen-dependent neoplasia; active deep vein thrombosis, pulmonary embolism, or a history of these conditions; active arterial thromboembolic disease (ie, stroke, myocardial infarction), or a history of these conditions; anaphylactic reaction or angioedema to PREMARIN; liver dysfunction or disease; thrombophilic disorders; pregnancy.

In a clinical trial, the most commonly reported (≥5%) adverse events for PREMARIN tablets that were statistically different than placebo included vaginal moniliasis, vaginitis, vaginal bleeding, dysmenorrhea, and leg cramps.



Indications

PREMARIN is indicated in the treatment of moderate to severe vasomotor symptoms due to menopause, treatment of moderate to severe symptoms of vulvar and vaginal atrophy due to menopause, and the prevention of postmenopausal osteoporosis.

When prescribing solely for the symptoms of vulvar and vaginal atrophy, topical vaginal products should be considered.

When prescribing solely for the prevention of postmenopausal osteoporosis, therapy should only be considered for women at significant risk of osteoporosis and non-estrogen medications should be carefully considered.



Click here for Full Prescribing Information, including boxed warning, and Patient Product Information.



REFERENCES: 1. Anderson GL, Limacher M, Assaf AR, et al; Women's Health Initiative Steering Committee. Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the Women's Health Initiative randomized controlled trial. JAMA. 2004;291(14):1701-1712. 2. Bachmann G, Nevadunsky NS. Diagnosis and treatment of atrophic vaginitis. Am Fam Phys. 2000;61(10):3090-3096. 3. Bachmann G, Bouchard C, Hoppe D, et al. Efficacy and safety of low-dose regimens of conjugated estrogens cream administered vaginally. Menopause. 2009;16(4):719-727. 4. Curb JD, Prentice RL, Bray PF, et al. Venous thrombosis and conjugated equine estrogen in women without a uterus. Arch Intern Med. 2006;166(7):722-780. 5. Data on file, Pfizer Inc. 6. Finkelstein JS. Osteoporosis. In: Goldman L, Ausiello D, eds. Cecil Textbook of Medicine. 22nd ed. Philadelphia, PA: Saunders; 2004:1547-1555. 7. Finkelstein JS, Brockwell SE, Mehta V, et al. Bone mineral density changes during the menopause transition in a multiethnic cohort of women. J Clin Endocrinol Metab. 2008;93(3):861-868. 8. Hedlund LR, Gallagher JC. The effect of age and menopause on bone mineral density of the proximal femur. J Bone Miner Res. 1989;4(4):639-642. 9. Jackson RD, Wactawski-Wende J, LaCroix AZ, et al; Women's Health Initiative Investigators. Effects of conjugated equine estrogen on risk of fractures and BMD in postmenopausal women with hysterectomy: results from the Women's Health Initiative randomized trial. J Bone Miner Res. 2006;21(6):817-828. doi:10.1359/JBMR.060312.10. Lindsay R, Gallagher JC, Kleerekoper M, Pickar JH. Effect of lower doses of conjugated equine estrogens with and without medroxyprogesterone acetate on bone in early postmenopausal women. JAMA. 2002;287(20):2668-2676. 11. Lynch C. Vaginal estrogen therapy for the treatment of atrophic vaginitis. J Women's Health. 2009;18(10):1595-1606. 12. North American Menopause Society. Estrogen and progestogen use in postmenopausal women: July 2008 position statement of the North American Menopause Society. Menopause. 2008;15(4):584-602. doi: 10.1097/gme.0b013e31817b076a. 13. North American Menopause Society. Estrogen and progestogen use in postmenopausal women: 2010 position statement of the North American Menopause Society. Menopause. 2010;17(2):242-255. 14. National Institutes of Health. National Institutes of Health State-of-the-Science Conference statement: management of menopause-related symptoms. Ann Intern Med. 2005;142(12 part 1):1003-1013. 15. Rossouw JE, Prentice RL, Manson JE, et al. Postmenopausal hormone therapy and risk of cardiovascular disease by age and years since menopause. JAMA. 2007;297(13):1465-1477. 16. Stearns V, Ullmer L, Lez JF, Smith Y, Isaacs C, Hayes DF. Hot flushes. Lancet. 2002;360(9348):1851-1861. 17. Stefanick ML, Anderson GL, Margolis KL, et al; WHI Investigators. Effects of conjugated equine estrogens on breast cancer and mammography screening in postmenopausal women with hysterectomy. JAMA. 2006;295(14):1647-1657. 18. US Food and Drug Administration. Estrogen and estrogen with progestin therapies for postmenopausal women.
http://www.fda.gov/Drugs/DrugSafety/InformationbyDrugClass/ucm135318.htm.
Updated June 22, 2010. Accessed June 13, 2011. 19. US Food and Drug Administration. Compounded menopausal hormone therapy questions and answers.
http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/PharmacyCompounding/ucm183088.htm.
Updated February 5, 2010. Accessed June 13, 2011. 20. US Food and Drug Administration. Menopause.
http://www.fda.gov/ForConsumers/ByAudience/ForWomen/WomensHealthTopics/ucm117978.htm.
Updated April 29, 2011. Accessed June 13, 2011. 21. Utian WH, Shoupe D, Bachmann G, Pinkerton JV, Pickar JH. Relief of vasomotor symptoms and vaginal atrophy with lower doses of conjugated equine estrogens and medroxyprogesterone acetate. Fertil Steril. 2001;75(6):1065-1079.