Bisphosphonates for breast cancer

Bisphosphonates are drugs that are used to help strengthen bones and reduce the risk of fractures and pain in bones that have been weakened by metastatic breast cancer. Examples include pamidronate (Aredia^®) and zoledronic acid (Zometa^®). They are given intravenously (IV).

Bisphosphonates may also help against bone thinning (osteoporosis) that can result from treatment with aromatase inhibitors or from early menopause as a side effect of chemotherapy. There are a number of medicines, including some oral forms of bisphosphonates, to treat loss of bone strength when it is not caused by cancer spread to the bones.

Bisphosphonates can have side effects, including flu-like symptoms and bone pain. They can also lead to kidney problems, so patients with poor kidney function may not be able to be treated with these drugs.

A rare but very distressing side effect of bisphosphonates is osteonecrosis (damage) in the jaw bones or ONJ. It can be triggered by having a tooth removed while getting treated with a bisphosphonate. ONJ often appears as an open sore in the jaw that won't heal. It can lead to loss of teeth or infections of the jaw bone. Doctors don't know why this happens or how to treat it, other than to stop the bisphosphonates. Maintaining good oral hygiene by flossing, brushing, making sure that dentures fit properly, and having regular dental checkups may help prevent this. Most doctors recommend that patients have a dental checkup and have any tooth or jaw problems treated before they start taking a bisphosphonate.