Which statement about bisphosphonate pharmacodynamics is true?

Which statement about bisphosphonate pharmacodynamics is true?

• A. They increase osteoclast activity.
• B. They reduce osteoclast function and number.
• C. They primarily stimulate osteoblasts.
• D. They have no effect on bone remodeling.

Answer: (B)

Bisphosphonates work by suppressing osteoclast-mediated bone resorption. They attach to bone surfaces and are taken up by osteoclasts during resorption. Inside the osteoclasts, they disrupt the mevalonate pathway, impairing protein prenylation and cytoskeletal function, which leads to osteoclast dysfunction and apoptosis. The net effect is a decrease in both the activity and the number of osteoclasts, slowing bone resorption and remodeling. They do not primarily stimulate osteoblasts, and their main impact is on resorption rather than a direct increase in bone formation. Because they reduce resorption, they certainly affect bone remodeling; claiming no effect on remodeling would be incorrect.

Bisphosphonates work by suppressing osteoclast-mediated bone resorption. They attach to bone surfaces and are taken up by osteoclasts during resorption. Inside the osteoclasts, they disrupt the mevalonate pathway, impairing protein prenylation and cytoskeletal function, which leads to osteoclast dysfunction and apoptosis. The net effect is a decrease in both the activity and the number of osteoclasts, slowing bone resorption and remodeling.

They do not primarily stimulate osteoblasts, and their main impact is on resorption rather than a direct increase in bone formation. Because they reduce resorption, they certainly affect bone remodeling; claiming no effect on remodeling would be incorrect.