Bisphosphonates bind strongly to bone and reduce bone resorption through effects on both osteoclasts and osteoblasts. Alendronate is a nitrogen-containing bisphosphonate that is commonly used in the treatment of osteoporosis and other metabolic bone diseases. It inhibits bone resorption in vitro with an IC50 value of 2 nM. In vivo, alendronate significantly increases (or prevents a decrease in) bone mineral density and reduces vertebral fractures.
