Biphosphonates are phosphate derivatives that bind to the surface of the bone, thereby blocking bone removal and decreasing bone
loss. Currently, there are three biphosphonates - alendronate [
Fosamax], etidronate [Didronal]) and risedronate [Actonel], that have been approved by the FDA for the prevention and treatment of osteoporosis. These medications have been shown to increase bone mass, prevent bone loss, and to decrease the incidence of bone fractures.