Bone Mineral Homeostasis

Question 1

• clotting of blood
• ossification of bone
• muscle contraction
• release of endocrine hormones and neurotransmitters

Answer 1

calcium

Question 2

treats:
- hypocalcemia due to dietary insufficiency or malabsorption states, renal disease, or hypoparathyroidism
- hypocalcemic tetany
- prophylaxis and treatment of osteoporosis
- toxicity: ectopic calcification

Answer 2

calcium

Question 3

• oral, cheap
• more likely to cause gas, bloating, constipation
• neutralizes gastric acid and can cause rebound acid secretion
• more concentrated calcium, smaller pills
• need to take with food

Answer 3

calcium carbonate

Question 4

• oral, fewer GI problems
• does not affect gastric pH
• can take without food

Answer 4

calcium citrate

Question 5

• for severe symptomatic hypocalcemia
• least irritating to veins of IV calcium preps
• rapid infusion can cause arrhythmias

Answer 5

IV calcium gluconate

Question 6

• formed in skin by UV irradiation and certain foods
• intrinsic (D3) and dietary (D3, D2) are inactive precursors that must be converted to active metabolites of which calcitriol is most active
• circulates bound to a binding protein
• regulates calcium homeostasis (bones increase bone formation and resorption, kidneys to increase tubular reabsorption, SI to increase calcium and phosphate absorption)

Answer 6

vitamin D

Question 7

vitamin D deficiency causes ________ resulting in abnormal and retarded bone growth

Answer 7

Rickets

Question 8

toxicities of _______ include hypercalcemia and hypercalciuria, causing n/v/decreased appetite, frequent urination, and renal failure

Answer 8

vitamin D

Question 9

vitamin D3 analog, has longer half life so it’s better for supplementation unless metabolism is compromised

Answer 9

cholecalciferol

Question 10

1,25-dihydroxyvitamin D, most active analog of vitamin D, used if kidney unable to convert active vitamin D

Answer 10

calcitriol

Question 11

• inadequate dietary intake
• inadequate exposure to sunlight
• renal dysfunction
• administration of anticonvulsants (phenobarbital, phenytoin) that increases its metabolism

Answer 11

vitamin D deficiency

Question 12

Treats:

• nutritional rickets
• metabolic rickets duet o genetic defect in renal hydroxylase or chronic renal failure, calcitriol used
• osteoporosis and osteomalacia
• psoriasis, topical calcipotriene
• hypoparathyroidism
• secondary hyperparathyroidism

Answer 12

pharmacological uses of vitamin D

Question 13

vitamin D form that has higher affinity for receptors in human tissues, more effective in increasing plasma D concentrations

Answer 13

D3

Question 14

vitamin D derivative that has lower affinity for the D binding protein and shorter half life

Answer 14

D2

Question 15

• analogs of pyrophosphate, suppress activity of osteoclasts and inhibit bone resorption
• used for osteoporosis, bone metastases, Paget’s, hypercalcemia

Answer 15

bisphosphonates

Question 16

• esophageal and gastric irritation
• osteonecrosis of the jaw
• renal failure
• side effects of what drug?

Answer 16

bisphosphonates

Question 17

etidronate, alendronate, and risedronate are ______ bisphosphonates

Answer 17

oral

Question 18

ibandronate is given _________ bisphosphonate give monthly or quarterly

Answer 18

oral and IV

Question 19

zoledronic acid and pamidronate are ______ bisphosphonates

Answer 19

IV

Question 20

administered SQ, stimulates new bone that is structurally normal, not recommended for use >2 years, black box warning for osteosarcoma

Answer 20

teriparatide (PTH1-34)

Question 21

increases bone mass, not as effective as bisphosphonates or teriparatide

Answer 21

calcitonin

Question 22

administed SQ biannually, suppresses bone resorption, could have immunosuppressive effects

Answer 22

denosumab (RANKL inhibitor)

Question 23

• reduce bone resorbing effects of PTH

- not recommended for postmenopausal osteoporosis due to effects on breast, uterus, and CV system

Answer 23

estrogens

Question 24

• stabilizes hydroxyapatite crystals in bone and teeth
• used to prevent dental caries
• toxicity at doses 3-5 mg/kg

Answer 24

fluoride

Question 25

• activates calcium sensing receptor in parathyroid gland

- used for secondary hyperparathyroidism in renal disease and parathyroid carcinoma

Answer 25

cinacalcet

Question 26

• decrease calcium absorption and increase excretion
• block bone formation
• can lead to osteoporosis

Answer 26

glucocorticoids

Question 27

• decrease renal calcium excretion
• can augment effects of PTH
• used for hypercalciuria

Answer 27

thiazide diuretics

Question 28

cholecalciferol, ergocalciferol, calcitriol, calcipotriene, doxercalciferal, paracalcitrol

Answer 28

vitamin D drugs

Question 29

etidronate, alendronate, risedronate, ibandronate, zoledronic acid, pamidronate

Answer 29

bisphosphonates