Drugs to strengthen your bones

Breast cancer

Bone strengthening therapy

Strengthening the bones

Strengthening the bones

Bone-strengthening drugs are used to treat ABC in the bone. Bisphosphonates and denosumab are drugs that work in slightly different ways to strengthen existing bone and reduce the damage caused by cancer. They also help control the level of calcium in the blood so it doesn’t become too high (this is called hypercalcaemia).


Bisphosphonates slow bone breakdown while allowing new bone to be produced as normal and are usually administered as a drip (infusion).

The main one used is zoledronic acid (Zometa) and it is given every three to four weeks.

Zoledronic acid is fully funded and licensed for use in New Zealand.

Denosumab (XGEVA)

Denosumab is a targeted therapy specifically for ABC in the bone.

It works by attaching to a substance called RANK-L, which is involved in causing bone to be broken down. It reduces bone loss, making bone complications (such as fracture) less likely to occur.

Denosumab is administered as an injection under the skin (subcutaneous) usually once every four weeks.

It is licensed for use in New Zealand, but is not funded.

Side effects of bisphosphonates and denosumab

The side effects are usually mild and may include:

  • nausea (feeling sick)
  • headaches
  • flu-like symptoms (such as chills and muscle aches)
  • damage to the bone in the jaw (osteonecrosis).

Very rarely, bisphosphonates and denosumab can damage the bone in the jaw (osteonecrosis). Osteonecrosis is hard to treat, so trying to prevent it (looking after your teeth and gums) is very important. Your oncologist will ask you to have a dental check-up before starting bone-strengthening drugs.

High levels of calcium in the blood (hypercalcaemia)