How do the bisphosphonates work and why can dosing be daily, weekly, monthly or yearly?
After entering the blood stream, bisphosphonate medications bind rapidly to bone. Drug not bound to bone rapidly passes out of the body through the kidney. The bisphosphonate medication remains stuck on the bone surface for a long time, where it decreases the functioning of bone-removing cells (osteoclasts). With reduced removal of old bone, the healthy balance of bone removal and bone formation can be re-established. Because the bisphosphonate medication remains on the surface of bone for a long time, daily dosing is not required. The interval between doses depends on the amount of bisphosphonate sticking to the bone, the length of time the bisphosphonate stays stuck on the bone, and the strength of the particular bisphosphonate in slowing the removal of bone by osteoclasts. Because the usual reason for postmenopausal osteoporosis is over-activity of osteoclasts (which removes bone), treatment with bisphosphonate restores bone removal to a level similar to that of a younger person, th
