The central role of estrogen deficiency as the pathophysiologic factor driving postmenopausal bone loss and years of clinical experience with estrogen therapy have made such therapy the current criterion standard. Estrogen therapy, however, is far from perfect. Estrogen acts on many of the body's tissues and not all of the effects are desirable. Estrogen-induced vaginal bleeding and breast tenderness lead to poor compliance with estrogen therapy. 1 Estrogen also has undesirable effects on the breasts and uterus.
Designer estrogens promise a safer, more tolerable estrogen that has traditional efficacy.
Physicians should be prepared to know how they will use these drugs in clinical practice. Bisphosphonates, such as alendronate and etidronate, have also received Canadian approval for preventing postmenopausal osteoporosis and are used as alternatives to estrogen for women who cannot tolerate estrogen or prefer not to commit to estrogen therapy. Placebo and treatment arms all received calcium supplementation. The study's primary end point was the BMD of the lumbar spine, hip, femoral neck, and total body, all of which were measured by ultrasonography. Other end points included endometrial thickness and lipid profile.