Kinder, bone mineral homeostasis part II

Question 1

what normally makes calcitonin

Answer 1

parafolicular cells of the thyroid

Question 2

principle effects of calcitonin

Answer 2

decrease serum Ca and PO4 by actions on bone and kidney

Question 3

calcitonin effects on bone

Answer 3

inhibits osteoclastic bone resorption

in time formation reduced as well

Question 4

calcitonin effects on kidney

Answer 4

dec Ca and PO4 resorption as well as reabsorption of Na K and Mg

Question 5

therapeutic use of calcitonin

Answer 5

disorders of increased skeletal remodeling (pagets and osteoporosis)

Question 6

adverse effects of calcitonin

Answer 6

nausea, hand swelling, urticaria, and intestinal cramping

Question 7

glucocorticoids actions in bone remodeling

Answer 7

antagonize vit D stimulated intestinal Ca transport, stimulate renal Ca excretion and block bone formation
decrease in total body Ca stores

Question 8

therapeutic use of glucocorticoids

Answer 8

reversing hyperCa assoc with lymphomas and granulomatous disease like sarcoidosis or in vit D intoxication

Question 9

prolonged administration of glucocorticoids can cause what

Answer 9

osteoporosis in adults and stunted skel muscle development in children

Question 10

how do estrogens affect bone

Answer 10

prevent accelerated bone loss during the immediate post-menopausal period
transiently increase bone in post menopausal women

Question 11

how does raloxifene work

Answer 11

partial agonist in bone but does not stimulate endometrial proliferation in post menopausal women

Question 12

therapeutic use of raloxifene

Answer 12

Tx and prevention post menopausal osteoporosis

Question 13

adverse effects of raloxifene

Answer 13

hot flashes, leg cramps, thromboembolism

Question 14

contraindications of raloxifene

Answer 14

women with active or pasty history of venous thromboembolism and women with CHD or risk facotrs for major coronary events including stroke

Question 15

MOA aldendronate (bisphosphanate)

Answer 15

analogs of pyrophosphate in which P-O-P is replaced with non hydrolyzable P-C-P bond

Question 16

where does alendronate concentrate

Answer 16

sites of active bone remodeling, incorporated into bone until the bone is remodeled and the bisphosphonate is released back into the acid mdeium

Question 17

alendronate effects on osteoclasts

Answer 17

directly inhibits

Question 18

when should patients take alendronate

Answer 18

with full glass of water at least 30 minutes prior to first meal

Question 19

therapeutic use of alendronate

Answer 19

osteoporosis, hyper Ca, Pagets

Question 20

adverse effects of alendronate

Answer 20

esophageal and gastric irritation (take with water)

subtrochanteric femur fractures from over suppression of bone turnover

Question 21

MOA denosumab

Answer 21

monoclonal Ab that prevents action of RANKL by binding it

Question 22

therapeutic use denosumab

Answer 22

post-menopausal osteoporosis and some cancers (prostate and breast)

Question 23

how is denosumab administered

Answer 23

SQ every 6 mo

Question 24

adverse effects of denosumab

Answer 24

increased risk infection because many other cells ahve RANKL
osteonecrosis of jaw and subtrochanteric fractures
can lead to transient hypoCa or comprised Ca regulatory mech like chronic kidney disease and Vit D deficiency

Question 25

signs of hyperCa

Answer 25

CNS depression, coma, death

Question 26

major causes Hyper Ca

Answer 26

thiazie Tx, hyper PTH and cancer

Question 27

less common causes of hyper Ca

Answer 27

hypercitaminosis D, sarcoidosis, thyrotoxicosis, milk alkali syndrome, adrenal insufficiency and immobilization

Question 28

Tx approach to hyper Ca

Answer 28

``` saline diuresis bisphosphonates calcitonin phosphate glucocorticoids ```

Question 29

why is saline diuresis used in hyper Ca

Answer 29

Most patients with severe hypercalcemia have a substantial component of prerenal azotemia due to dehydration which prevents kidney from compensating for the rise in serum calcium by excreting more calcium in the urine.

Question 30

calcitonin use in hyper Ca

Answer 30

Seldom restores calcium to normal but lack of toxicity permits frequent administration at high doses. Effects seen within 4-6 hours, lasts 6-10 hours.

Question 31

phosphate use in hyper Ca

Answer 31

Fastest way to decrease serum calcium but hazardous if not done properly. Give IV phosphates slowly over 6-8 hours and switch to oral products once symptoms clear.

Question 32

Risks associated with IV phosphates

Answer 32

sudden hypocalcemia, ectopic calcification, acute renal failure, hypotension.

Question 33

role of glucocorticoids in hyper Ca

Answer 33

no clear role

Question 34

main features of hypoCa

Answer 34

neuromuscular tetany paresthesias, laryngospasm, muscle cramps, seizures

Question 35

major causes hypoCa

Answer 35

hypoPTH, Vit D def, chronic kidney disease and malabsorption

Question 36

Tx approach to hypoCa

Answer 36

Ca IV, IM PO | VIT D, calcitriol when need rapid action

Question 37

why do we do slow infusions of Ca gluconate in severe hypoCa

Answer 37

to prevent cardiac arrhythmias

Question 38

what is used for IV Ca

Answer 38

Ca gluconate because less irritating to veins than Ca Cl

Question 39

what are the oral formulations fo Ca

Answer 39

Ca carbonate Ca lactate Ca PO4 Ca citrate

Question 40

what is the preferred oral Ca

Answer 40

Ca carbonate because high % of Ca, avaialble, low cost and antacid properties

Question 41

hyperPO4 is a common ocmplicaiton of what

Answer 41

renal failure hypoPTH Vit D intoxication and tumoral calcinosis

Question 42

what is Tx for hyperPO4

Answer 42

dietary restriction and use of PO4-binding gels like sevelamer and Ca supplements

Question 43

what to avoid in hyperPO4

Answer 43

aluminum containing antacids because can cause aluminum assoc bone disease

Question 44

Tx primary hyperPTH

Answer 44

surgery, vit D supp

Question 45

Tx secondary hyperPTH

Answer 45

cinacalcet

Question 46

Tx hypoPTH

Answer 46

Ca and Vit D supp

Question 47

Tx Vit D deficiency

Answer 47

Vit D replacement

Question 48

Tx options for osteoporosis

Answer 48

``` bisphosphonates SERMs Ca and Vit D supp teriparatide calcitonin denosumab ```

Question 49

What is used to Tx Pagets

Answer 49

Calcitonin and bisphosphanates are first line agents

Question 50

Tx with bisphosphanates should not exceed what time period

Answer 50

6 mo, but can be repeated after "holiday" from drug