To understand how bisphosphonates work, it helps to know a bit about normal bone activity.
Normal bone activity
Your bones are made of living tissue, and are constantly changing. In healthy bones, specialised bone cells constantly break down and replace bone tissue.
These specialised bone cells are:
- osteoclasts – which break down old bone
- osteoblasts – which build new bone
This process is called bone remodelling. There is a very good balance between the rates of bone breakdown and growth, which keeps bones strong and healthy.
What bisphosphonates do
Bisphosphonates target the areas of higher bone turnover. The osteoclast cells absorb the bisphosphonate drug, which slows down their activity and reduces bone breakdown.
There are several different types of bisphosphonates, and they each work slightly differently. Doctors are still learning more about the exact ways in which bisphosphonates work.
We know that bisphosphonates can:
- interfere with the formation of osteoclasts
- make osteoclasts self destruct or die early
- change the signalling between osteoclasts and osteoblasts
- form a barrier between the bone and the osteoclast
Researchers have found that bisphosphonates can prevent or slow down the development of myeloma and secondary bone cancers in some people.
Cancer cells seem to be attracted to an environment where bones are being broken down. Researchers hope that stopping this process could slow cancer growth and help people live longer, as well as reduce bone damage.