Effect of pamidronate on the mechanical properties of canine bone.

Pamidronate (Aredia) has been used in the treatment of hypercalcemia of malignancy, in Paget's disease of bone, and in osteoporosis to prevent bone resorption. In a 3-month study, intermittent intravenous infusions of pamidronate in dogs did not change the mechanical properties of cortical bone, either in torsion or bending. However, such treatment increased the compressive stiffness and torsional strength of trabecular specimens taken from vertebrae. In a 1-year study, oral administration of pamidronate at various doses produced a linear increase in the elastic modulus of trabecular bone with the square root of the dose and no change in cortical bone. Finally, in a 2-year study (1 year on pamidronate followed by 1 year recovery), no differences were found in the mechanical properties of whole bone whatever dose was given.