Zoledronic acid belongs to a group of drugs called bisphosphonates. Bisphosphonates are commonly used to treat bone thinning (osteoporosis).
In certain situations, bisphosphonates can help protect your bones against some of the effects of secondary bone cancer, such as pain and bone weakness. Secondary bone cancer occurs when the original (primary) cancer spreads to form a new cancer (secondary cancer or metastasis) in the bone.
Zoledronic acid is often given alongside other cancer treatments. As well as being used for some types of secondary bone cancer, it has been shown to be effective for people with myeloma (a cancer of the plasma cells, which are a type of blood cell). It is also used to lower a raised calcium level in the blood.