Raloxifene belongs to which class of osteoporosis medications?

• A. Denosumab
• B. Selective estrogen receptor modulators (SERMs)
• C. Calcitonin
• D. Bisphosphonates

Answer: (B)

Raloxifene is a selective estrogen receptor modulator, a class of osteoporosis medications that work by modulating estrogen receptors differently in various tissues. In bone, it acts as an estrogen receptor agonist, helping to preserve bone density and reduce osteoclast activity. In contrast, in breast tissue (and the uterus) it acts as an antagonist, which lowers the risk of estrogen receptor–positive breast cancer and avoids stimulating the endometrium. That tissue-specific action is what defines its classification as a SERM.

Other listed drug types work through different mechanisms, which is why they aren’t the correct category for raloxifene. Denosumab is a monoclonal antibody that inhibits RANKL to prevent osteoclast formation. Calcitonin is a peptide hormone that reduces bone resorption with a different, less potent mechanism. Bisphosphonates bind to bone and directly inhibit osteoclast-mediated resorption.