Denosumab, a fully human monoclonal antibody used in osteoporosis, acts by which mechanism?

• A Inhibits osteoclast formation and function by binding RANK ligand ✓
• B Inhibits osteoclast activity by binding to hydroxyapatite on bone surfaces
• C Stimulates osteoblast activity via intermittent PTH receptor activation
• D Inhibits bone resorption by blocking the vacuolar ATPase on osteoclasts

Explanation

Denosumab binds RANK ligand (RANKL), preventing RANKL from activating RANK receptors on osteoclast precursors, thereby inhibiting osteoclast formation, function, and survival. Alendronate binds hydroxyapatite. Teriparatide activates PTH receptors. Cathepsin K inhibitors (like odanacatab, though withdrawn) target osteoclast protease, not vacuolar ATPase.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.