Bone Drugs

These flashcards cover key terms and concepts related to drugs affecting bone mineral homeostasis, including hormonal agents and their mechanisms of action.

Calcitriol

Active form of vitamin D

stimulates intestinal and renal reabsorption of Calcium and phosphate

enhances bone mineralization and release of FGF23 from osteocytes

inhibits release of parathyroid hormone

PTH (Parathyroid Hormone)

Released during hypocalcemia to increase serum calcium

Promotes bone demineralization

Increases renal calcium absorption in exchange for phosphate

Increases intestinal absorption of calcium and phosphate (activates D3 in kidney)

Phosphaturic Action

Increased phosphate excretion after PTH action

PTH Inhibition

hypercalcemia

vitamin D3

FGF23 (Fibroblast Growth Factor 23)

released from the bone by increased serum levels of phosphate, PTH, and vitamin D3

Calcitonin (CT)

Hormone that lowers blood calcium and phosphate levels by inhibiting osteoclastic bone resorption.

Bisphosphonates

Class of drugs that inhibit osteoclast activity leading to reduced bone resorption and are used to treat conditions like osteoporosis.

Denosumab

A monoclonal antibody that inhibits RANKL, reducing osteoclast formation and activity, used in the treatment of osteoporosis.

Romosozumab

An anabolic agent that inhibits sclerostin, promoting bone formation and reducing resorption, approved for severe postmenopausal osteoporosis.

RANK Ligand (RANKL)

A protein that promotes osteoclast formation, activation, and survival, playing a key role in bone remodeling.

Osteoprotegerin (OPG)

A naturally occurring protein that acts as a decoy receptor for RANKL, preventing it from activating osteoclasts.

Vitamin D Toxicity

A condition resulting from excessive vitamin D leading to hypercalcemia, with symptoms including weakness, nausea, and kidney stones.