Bisphosphonates are used to treat bone-related conditions, such as osteoporosis, Paget's disease of bone, and bone complications from cancer. Bisphosphonates work by slowing down the cells that break down bone, which helps to maintain or increase bone density. These medications come in different forms, including oral pills and injections. Examples include alendronate (Fosamax), ibandronate, risedronate (Actonel), and zoledronic acid (Reclast).