Zoledronic injection is a medication that is used to treat bone diseases such as osteoporosis and Paget's disease. It is a bisphosphonate, which means it works by slowing down the rate of bone breakdown and increasing bone mass. Zoledronic injection is administered intravenously, usually once a year. The most common side effects include flu-like symptoms and pain at the injection site. Serious side effects include kidney damage and severe bone, joint, and/or muscle pain. Before taking zoledronic injection, it is important to tell your doctor about all other medications and supplements you are taking.