What's the only drug that increases bone formation?
Teriparatide -- does not try to block bone resorption, as all other osteoporosis drugs do.
What is a synthetic vitamin D2 analong that undergoes metabolic activation in vivo to form active vit D2 that is used to treat secondary hyperparathyroidism associated with chronic renal failure?
Doxercalciferol
What is a synthetic analog of active vitamin D2 that is used to treat secondary hyperparathyroidism associated with chronic renal failure?
Paricalcitol
Commonly used to prevent and treat osteoporosis, rickets and osteomalacia
Calcitriol = active vitamin D
What is dihydrotachysterol?
A synthetic analog of active vitamin D
Name a drug used to treat psoriasis
Calcipotriol or Calcipotriene = topical derivative of calcitriol
Mechanisms of bisphosphates
-- have P-C-P which is nonhydrolyzable compared to Pyrophosphate P-O-P found in
bone hydroxyapatite --> P-O-P easily destroyed by osteoclasts
-- adsorb to hydroxyapatite and become a part of the bone structure.They are slowly released from the bone during the bone remodeling. Biphosphonates prevent bone resorption by inhibiting
osteoclast activity
– Prevent attachment of osteoclast to bone.
– Decrease the activity of osteoclast .
Uses of bisphosphonates
Osteoporosis (even induced by steroids).
Paget’s disease of bone.
Hypercalcemia of malignancy.
Adverse effects of bisphosphates
Esophagitis
GIT distress
Osteonecrosis of the jaw
Estrogen use in osteoporosis
Inhibit IL-1 and TNF and thus decrease osteoclasts differentiation/activation
A selective estrogen receptor modulator and its uses
Raloxifene -- used for prevention/treatment of osteoporosis in women -- decreases osteoclast activity w/o increasing osteoblast activity
When is calitonin secreted? From where?
Secreted in response to increases in plasma calcium by the parafollicular cells of the thyroid gland
Effects of calcitonin
Main effect = to lower serum calcium and phosphate
Inhibits osteoclast activity, decreases bone resorption and reduces bone pain
Inhibits the reabsorption of calcium and phosphate from the renal tubules
Uses of calcitonin
Tx of Paget's disease
Postmenopausal osteoporosis
Hypercalcemia
Effects of flouride
Stimulates new bone formation
Increases bone crystal size and renders the bone more resistant to resorption
A monoclonal Ab for Tx of osteoporosis
Denosumab
Mechanism of denosumab
Binds RANKL on osteoblasts which then prevents osteoblasts from binding RANK on pre-osteoclasts and forming mature osteoclasts -- thereby protects bone from osteoporosis