Bisphoshonates act by
Increasing the Osteoid formation
Increasing the mineralization of Osteoid
Decreasing the osteoclast mediated resorption of bone
Decreasing the parathyroid hormone receptors
Refer Katzung 10/e p713 bisphoshonates are used for the treatment of post menopausal osteoporosis, steroid induced osteoporosis, Pagets disease and hypercalcemia of malignancy
Endocrinology