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It is estimated that every seven seconds a Canadian woman turns 50. This means that within the next couple of decades the number of postmenopausal women will double. Many of these women will find it difficult to decide how to manage their postmenopausal health. The new selective estrogen receptor modulator (SERM), raloxifene (Evista, Lilly), offers women and health-care professionals another choice.
What are SERMs?
SERMs are a group of synthetic compounds that exhibit varying degrees of agonist or antagonist activity at different estrogen receptor sites. Their selectivity has resulted in the classification selective estrogen receptor modulators.
Are SERMs estrogens?
Although labelled "designer estrogens" by the media, these agents are not estrogens, even though they affect estrogen receptors throughout the body. They belong to chemical groups such as triphenylethylenes, benzothiophenes, benzopyrans, tetrahydronaphthylenes and other distinct chemical compounds.
Which SERMs are available in Canada?
Tamoxifen, clomiphene and raloxifene are available in Canada. Some agents under investigation include droloxifene, levomeloxifene, idoxifene and toremifene.
What are the indications for the newest SERM, raloxifene?
Raloxifene has an indication in Canada for the prevention of osteoporosis in postmenopausal women. It is not recommended for women of childbearing age, children, men or perimenopausal women. It is not currently indicated for the treatment of osteoporosis.
How does raloxifene work on bone?
Raloxifene blocks bone resorption. This results in an increase in bone density. Recent interim data from the MORE (Multiple Outcomes with Raloxifene Evaluation) trial also suggest a decrease in new vertebral fractures by approximately 50% when compared to placebo (participants also received 500mg elemental calcium and 400 IU vitamin D daily).
How does raloxifene compare to other agents used to prevent osteoporosis?
There are no studies that directly compare estrogen, raloxifene and bisphosphonates for efficacy. Available information suggests that generally estrogen increases bone mineral density (BMD) by about 3% to 5%, bisphosphonates increase BMD about 4% and raloxifene about 2.4% All three therapies have been shown to decrease the fracture...