Bone Mineral Homeostasis Agents

Question 1

MOA of calcipotriol

Answer 1

analog of calcitriol (active Vit D). used in treatment of psoriasis.

Question 2

ADE of calcipotriol

Answer 2

can cause hypercalcemia if too much is given

Question 3

MOA of Cinacalcet

Answer 3

Calcium sensor recepetor mimetic (CaSR).

binds allosterically to CaSR and allows PTH suppression at lower Ca concentrations, lowering PTH.

Question 4

ADE of Cinacalcet

Answer 4

lowers PTH so overdose could result in hypoparathyroidism and low plasma Ca.

Question 5

MOA of Desunomab

Answer 5

RANKL antibody prevents osteoclast formation and decreases osteoporosis

Question 6

MOA of fluoride

Answer 6

F- binds to Ca and prevents dental cavities, blood clotting, and osteoporosis.

Question 7

ADE of fluoride

Answer 7

can cause osteosclerosis (hydroxyapatite replaced by fluorapatite. Also can mottle the enamel (fluorosis)

Question 8

MOA of ibandronate

Answer 8

2nd gen bisphosphonate. potent

Question 9

ADE of ibandronate

Answer 9

Osteonecrosis of jaw and Severe teeth problems. Often requires extraction and results in infection.

Question 10

MOA of raloxifene

Answer 10

selective estrogen receptor modulator. Beneficial effects of estrogen on bones without stimulating breast cancer.

Question 11

MOA of risedronate

Answer 11

3rd gen bisphosphonate. Inhibits bone resorption

Question 12

ADE of risedronate

Answer 12

Osteonecrosis of jaw and Severe teeth problems. Often requires extraction and results in infection. 3rd gen bisphosphonates are worse.

Question 13

MOA of teriparatide

Answer 13

hrPTH 1-34. Exogenous PTH. In high doses promotes bone resporption.
In LOW doses promotes bone FORMATION. (good for osteoporosis after bisphosphonates)

Question 14

ADE of teriparatide

Answer 14

May stimulate IGF-1

Question 15

MOA of zoledronic acid

Answer 15

3rd gen bisphosphonate. more potent

Question 16

ADE of zoledronic acid

Answer 16

Osteonecrosis of jaw and Severe teeth problems. Often requires extraction and results in infection. 3rd gen bisphosphonates are worse.

Question 17

What is the therapeutic role of bisphosphonate therapy in osteoporosis? What are its limitations?

Answer 17

inhibits bone resporption. Effective to treat osteoporosis. Useful in preventing bone loss in cancer patients.

Jaw osteonecrosis and tooth loss/infection.

Question 18

What are the 3 calcitropic hormones of the body?

Answer 18

PTH, calcitonin, calcitriol (active Vit D)

Question 19

What form is the majority of calcium in the blood found?

Answer 19

50% is duffusable, free calcium

Question 20

What is the main binding protein of calcium?

Answer 20

albumin (40% of total plasma calcium is bound to it)

Question 21

What are the 3 functions of PTH?

Answer 21

increase bone resorption
increase kidney reabsorption of Ca (decrease P reabsorption)
increase active Vitamin D

Question 22

What are 3 major actions of calcitonin?

Answer 22

decrease bone resporption
decrease kidney calcium reabsorption
decrease active vitamin D

Question 23

Where is calcitonin produced?

Answer 23

in the C cells (parafollicular) between thyroid follicles as well as lung and GI tract

Question 24

What is the main function of Vit D?

Answer 24

increase plasma Ca.
increase GI uptake of Ca and P
increase bone resoprtion

Question 25

What detects hypocalcemia? Hypercalcemia?

Answer 25

Hypocalcemia detected by parathyroid which produces PTH.

Hypercalcemia detected by parafolicular cells of thyroid (C cells), which produce calcitonin.

Question 26

What does PTH do to cAMP levels?

Answer 26

increases them. Also increases them in urine.

Question 27

What does FGF-23 do?

Answer 27

inhibits production of active Vit D. (1,25)

Opposes PTH in kidney.

Question 28

ADE of bisphosphonates

Answer 28

Osteonecrosis of jaw and teeth problems because they are exposed during oral delivery. 80% of cases have dental extraction.

Question 29

MOA of alendronate?

Answer 29

2nd gen bisphosphonate. 10-100x more potent than 1st gen.

Question 30

ADE of alendronate?

Answer 30

Osteonecrosis of jaw and teeth problems because they are exposed during oral delivery. 80% of cases have dental extraction.