Which class of medication is a known risk for osteoporosis when used long-term?

• A. Diphenoxylate
• B. Sulfasalazine
• C. Prednisone
• D. Propantheline

Answer: (C)

Long-term use of glucocorticoids, like prednisone, is a well-known cause of secondary osteoporosis. These drugs disrupt bone remodeling in several ways: they suppress the formation and function of osteoblasts (the cells that build bone) and promote osteoblast and osteocyte death, which reduces new bone formation. They also increase osteoclast activity via changes in signaling molecules such as RANKL and reduce the protective effects of osteoprotegerin. In addition, glucocorticoids decrease calcium absorption from the gut and increase calcium loss in the urine, further lowering bone mineral density. The net effect is a rapid loss of bone mass and a higher risk of fractures, particularly in the spine and hip, with extended use or higher doses.

Other medications listed don’t have this strong, direct impact on bone remodeling with long-term use, so they are not typically associated with osteoporosis to the same degree.