Sujet de la discussion : MedeSpace.Net :: United State Médical Licensing Examination

Publié par La Pharmacienne le 11-12-2008 00:45
#18

This one is really hard... ;)

Choose the one best response to this question.

All the following therapies have been shown to reduce the risk of hip fractures in postmenopausal women with osteoporosis except :


A. alendronate
B. estrogen
C. parathyroid hormone
D. raloxifene
E. risedronate
F. vitamin D plus calcium


The answer
is D.

>>> The selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene act in a fashion similar to that of estrogen in decreasing bone turnover and bone loss in postmenopausal women. These agents have been shown to decrease the risk of invasive breast cancer. Raloxifene, which is approved for the prevention of osteoporosis, reduces the risk of vertebral fractures by 30 to 50%. There are no data confirming a similar effect on nonvertebral fractures. Optimal calcium intake reduces bone loss and suppresses bone turnover. Vitamin D plus calcium supplements have been shown to reduce the risk of hip fractures by 20 to 30%. The bisphosphonates alendronate and risedronate are structurally related to pyrophosphate and are incorporated into bone matrix. They reduce the number of osteoclasts and impair the function of those already present. Both have been shown to reduce the risk of vertebral and hip fractures by 40 to 50%. One trial found that risedronate reduced hip fractures in osteoporotic women in their seventies but not in older women without osteoporosis. Risedronate may be administered weekly. The newer bisphosphonates zoledronate and ibandronate may be dosed yearly or monthly. A daily injection of exogenous parathyroid hormone analogue superimposed on estrogen therapy produced increases in bone mass and decreased vertebral and nonvertebral fractures by 45 to 65%. There are no published studies of combinations of parathyroid hormone and SERMs or bisphosphonates.