Bone Mineral Homeostasis Agents Flashcards
MOA of calcipotriol
analog of calcitriol (active Vit D). used in treatment of psoriasis.
ADE of calcipotriol
can cause hypercalcemia if too much is given
MOA of Cinacalcet
Calcium sensor recepetor mimetic (CaSR).
binds allosterically to CaSR and allows PTH suppression at lower Ca concentrations, lowering PTH.
ADE of Cinacalcet
lowers PTH so overdose could result in hypoparathyroidism and low plasma Ca.
MOA of Desunomab
RANKL antibody prevents osteoclast formation and decreases osteoporosis
MOA of fluoride
F- binds to Ca and prevents dental cavities, blood clotting, and osteoporosis.
ADE of fluoride
can cause osteosclerosis (hydroxyapatite replaced by fluorapatite. Also can mottle the enamel (fluorosis)
MOA of ibandronate
2nd gen bisphosphonate. potent
ADE of ibandronate
Osteonecrosis of jaw and Severe teeth problems. Often requires extraction and results in infection.
MOA of raloxifene
selective estrogen receptor modulator. Beneficial effects of estrogen on bones without stimulating breast cancer.
MOA of risedronate
3rd gen bisphosphonate. Inhibits bone resorption
ADE of risedronate
Osteonecrosis of jaw and Severe teeth problems. Often requires extraction and results in infection. 3rd gen bisphosphonates are worse.
MOA of teriparatide
hrPTH 1-34. Exogenous PTH. In high doses promotes bone resporption.
In LOW doses promotes bone FORMATION. (good for osteoporosis after bisphosphonates)
ADE of teriparatide
May stimulate IGF-1
MOA of zoledronic acid
3rd gen bisphosphonate. more potent
ADE of zoledronic acid
Osteonecrosis of jaw and Severe teeth problems. Often requires extraction and results in infection. 3rd gen bisphosphonates are worse.
What is the therapeutic role of bisphosphonate therapy in osteoporosis? What are its limitations?
inhibits bone resporption. Effective to treat osteoporosis. Useful in preventing bone loss in cancer patients.
Jaw osteonecrosis and tooth loss/infection.
What are the 3 calcitropic hormones of the body?
PTH, calcitonin, calcitriol (active Vit D)
What form is the majority of calcium in the blood found?
50% is duffusable, free calcium
What is the main binding protein of calcium?
albumin (40% of total plasma calcium is bound to it)
What are the 3 functions of PTH?
increase bone resorption
increase kidney reabsorption of Ca (decrease P reabsorption)
increase active Vitamin D
What are 3 major actions of calcitonin?
decrease bone resporption
decrease kidney calcium reabsorption
decrease active vitamin D
Where is calcitonin produced?
in the C cells (parafollicular) between thyroid follicles as well as lung and GI tract
What is the main function of Vit D?
increase plasma Ca.
increase GI uptake of Ca and P
increase bone resoprtion
What detects hypocalcemia? Hypercalcemia?
Hypocalcemia detected by parathyroid which produces PTH.
Hypercalcemia detected by parafolicular cells of thyroid (C cells), which produce calcitonin.
What does PTH do to cAMP levels?
increases them. Also increases them in urine.
What does FGF-23 do?
inhibits production of active Vit D. (1,25)
Opposes PTH in kidney.
ADE of bisphosphonates
Osteonecrosis of jaw and teeth problems because they are exposed during oral delivery. 80% of cases have dental extraction.
MOA of alendronate?
2nd gen bisphosphonate. 10-100x more potent than 1st gen.
ADE of alendronate?
Osteonecrosis of jaw and teeth problems because they are exposed during oral delivery. 80% of cases have dental extraction.
