Low-Dose Tamoxifen for Combination Hormone Replacement Therapy Users

Abstract

Despite a dramatic reduction in postmenopausal hormone use after the initial publication of the Women’s Health Initiative results, 1-4 a substantial number of women continue to use some form of hormonal supplementation predominately to control menopausal symptoms. The conjugated equine estrogen Premarin (Wyeth Pharmaceuticals, Madison, NJ) is the 22nd most frequently prescribed brand name drug in the United States with more than 13 million prescriptions issued in 2006. 5 Almost 3 million prescriptions were issued in 2006 for Prempo (Wyeth Pharmaceuticals) a combination of an androgenic progestin with conjugated equine estrogen. 5 As the preponderance of clinical trial data indicating an increased risk of breast cancer and an unfavorable global health index has been for conjugated equine estrogens and progestins, interest in more physiologic types of hormone replacement has soared. These so-called bioidentical forms of hormone replacement include estradiol, estriol, testosterone, and progesterone, given as either single agents or compounded together and administered as pills, troches, transdermal patches, creams, or vaginal gels. More than 4 million brand name estradiol patches are currently sold annually. 5 Change in risk of breast cancer by the use of postmenopausal hormones may be dependent on the type of drug(s) and dose, route of administration, prior oophorectomy, age at initiation, and duration of use. Women using standard dose oral or transdermal estrogen without a progestin might anticipate either no increase or