Final answer:
Bisphosphonates work by inhibiting the activity of osteoclasts, thus slowing down bone breakdown and preserving bone density to prevent fractures. They are used to treat Paget's disease and osteoporosis, but long-term usage can lead to brittle bones.
Step-by-step explanation:
Bisphosphonates are medications used to treat and prevent bone diseases such as Paget's disease and osteoporosis. They function by decreasing the activity of osteoclasts, which are cells that break down bone tissue. This allows the process of bone remodeling to balance out, as the breakdown of old bone is slowed, permitting the rebuilding of bone to keep pace. Maintaining bone density through this mechanism is crucial in reducing the risk of fractures.
However, bisphosphonate treatment is generally recommended for a limited period, typically not exceeding three to four years, due to the potential for adverse side effects, including the increased risk of brittle and worn-out bones leading to fractures if used long term.