Alendronate: preclinical studies.

Alendronate is an aminobisphosphonate that was approved recently for the treatment of osteoporosis. Studies in ovariectomized rats and baboons have demonstrated the efficacy of this drug in animal models of osteoporosis. Alendronate prevented bone loss and increased bone mass and bone strength, relative to estrogen-deficient controls. Histomorphometric and biomechanical studies in rats, dogs, pigs, and primates have shown that, after alendronate treatment at multiples of the human dose for as long as 3 years, bone quality is normal. Alendronate mode of action studies show inhibition of bone resorption and bone turnover at the tissue level and inhibition of osteoclast activity at the cellular level.