Bisphosphonates are used in all of the followingconditions except

Bisphosphonates are analogs of pyrophosphate. They have a common structure, P-C-P, similar to the structure of the native pyrophosphate P-O-P found in bone hydroxyapatite. Mechanism of Action The bisphosphonates inhibit bone resorption by binding to the hydroxyapatite crystals of bone. (The bisphosphonates have a strong affinity for bone, targeting especially bone surfaces undergoing remodeling) When osteoclasts first attach to bone in the active resorptive sites, the bisphosphonates are released from that hone. The release of these compounds locally prevents fuher osteoclastic attachment to those resorptive surfaces. The bisphosphonates also may inhibit resorption by inducing apoptosis of osteoclasts and by inhibiting release of interleukins and other compounds involved in bone resorption. The net result of action of these compounds is inhibition of bone osteoclastic resorption. Uses They are used extensively in conditions characterized by osteoclast-mediated bone resorption. including - Osteoporosis (postmenopausal osteoporosis, idiopathic and steroid induced osteoporosis) - Paget's disease, - Osteolytic bone metastasis, and - Hypercalcemia of malignancy Recent evidence suggests that second- and third-generation bisphosphonates also may be effective anticancer drugs. (May have some use in prostate cancer) Currently three bisphosphonates are available in India- Etidronate, Pamidronate and Alendronate. ** Other bisphosphonates, not yet available in India are Tiludronate, Risedronate, Zolendronate and lbandronate.