What is Evista® (raloxifene)? What is a SERM, and why is it effective in the treatment of osteoporosis?
Evista (raloxifene) is the only FDA-approved estrogen agonist/antagonist for the prevention and treatment of osteoporosis in postmenopausal women. Evista used to be called a selective estrogen receptor modulator (or SERM), until September 2007 when the FDA changed the name for this class of medications to estrogen agonist/antagonist. Many clinicians still use the term "SERM." You may be more familiar with tamoxifen, an estrogen agonist/antagonist used in the treatment of breast cancer. An estrogen agonist/antagonist binds with some estrogen receptor sites around the body. Although raloxifene is not a hormone, it has an estrogen-like effect in some body tissues such as bone and has an estrogen-blocking effect on other tissues such as breast and uterus.
Evista increases BMD decreases the risk of fractures, and is FDA-approved for the prevention and treatment of osteoporosis in postmenopausal women. The dosage of Evista for both osteoporosis treatment and prevention is 60 mg per day taken as one tablet. Evista, unlike the bisphosphonates, may be taken with or without food. In addition to Evista's positive effects on bone, it also decreases low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol) as well as total cholesterol, but may actually increase triglyceride levels and therefore should be used with caution in women with preexisting high triglycerides and should not be used for prevention of heart disease. Evista reduces the risk for developing breast cancer and is FDA-approved for reducing risk for invasive breast cancer among postmenopausal women with osteoporosis and among postmenopausal women with high risk for invasive breast cancer. Evista's positive effects on bone do not last. Once treatment is stopped, bone loss will resume.
Major side effects seen with Evista are blood clots and stroke. Therefore, the FDA has required a black-box warning on Evista product information identifying these risks. For this reason it is contraindicated in women with a history of blood clots in veins or arteries. Evista can also cause hot flashes. If you already have hot flashes associated with postmenopause, you may want to consider a different medication for osteoporosis. You should not take Evista if you are on either estrogen therapy (ET) or estrogen-progestin therapy (EPT). Evista, however, might be prescribed with a bisphosphonate by a specialist (see Question 67). Evista may represent a good option for post-menopausal women who are not experiencing significant menopausal symptoms or are reluctant to go on ET or EPT for the prevention or treatment of osteoporosis, especially if they have concerns about breast cancer (see Questions 64-66).
If you already have hot flashes associated with postmenopause, you may want to consider a different medication for osteoporosis.
Evista is contraindicated in premenopausal women, women of childbearing age, in pregnancy, and in children, although there is a clinical trial evaluating the effect of Evista on endometriosis in women who are aged 18 to 45. Evista should never be given during pregnancy. Evista is not FDA-approved for use in pre-menopausal women.
A recent 3-year study of women taking 120 mg of Evista per day showed a 33% decrease in the risk for mild cognitive impairment (mental activities of thinking, learning, and memory). In this study, women taking the usual dosage of 60 mg per day did not see any improvement. The benefits were only found in those taking a double dosage (120 mg) daily. While mild cognitive impairment can be a precursor to Alzheimer's, this study did not show a reduction in cases of Alzheimer's; Alzheimer's takes longer than 3 years to develop. More information about Evista is in Table 13.