IC14

Question 1

Role of Vit D

Answer 1

helps Calcium to be absorbed from GIT

Question 2

What happens when there is low Ca

Answer 2

PTH secretion will incr, causing incr bone resorption and reabsorption of Ca in renal distal tubule

Question 3

At clinical doses, PTH analogues act more like a _____

Answer 3

anabolic agent

Question 4

Osteoclast stimulates bone____

Answer 4

resorption

Question 5

Osteoblast stimulates bone___

Answer 5

growth

Question 6

RANKL and sclerostin are produced by ____

Answer 6

osteocyte

Question 7

Role of sclerostin

Answer 7

Sclerostin binds to osteoblast -> inhibit WNT signalling -> repress dy/dx of osteoblast & ability to grow new bone

Question 8

Role of RANKL

Answer 8

Stimulates osteoclast to break down bone

Question 9

Example of RANKL inhibitor

Answer 9

Denosumab

Question 10

Role of anti-resorptive agents

Answer 10

Blocks bone breakdown

Question 11

Examples of anti-resorptive agents

Answer 11

• Bisphosphonates
• denosumab
• oestrogen
• calcitonin

Question 12

MOA of bisphosphonates

Answer 12

Slow bone loss by incr osteoclast cell death

Question 13

In what situation is bisphosphonate use > 5 years appropriate?

Answer 13

10yr total fracture risk > 20% OR prior vertebrae fracture

Question 14

MOA of denosumab

Answer 14

Human mAb Inhibits RANKL -> prevents osteoclast development

Question 15

Administration of denosumab (route & frequency)

Answer 15

SC injection every 6 months

Question 16

What to co-administer with denosumab

Answer 16

1000mg Ca +/- (min) 400 IU vit D daily

Question 17

Discontinuation of denosumab may cause ___

Answer 17

Risk of spinal column fractures

Question 18

Oestrogens MOA

Answer 18

Helps maintain bone density

Question 19

What is raloxifene

Answer 19

Selective oestrogen receptor modulator

Question 20

MOA of raloxifene

Answer 20

Mixed oestrogen receptor agonism and antagonism
-> Mimics effects of oestrogen on bone density in postmenopausal women.

Question 21

Risk of using oestrogen therapy

Answer 21

1. Incr risk of breast cancer
2. Incr risk of blood clots

Question 22

What is calcitonin and how is it secreted

Answer 22

Peptide hormone secreted by parafollicular cells of thyroid gland

Question 23

Dosage forms for calcitonin

Answer 23

IV/ IM/ SC/ nasal spray route

Question 24

Examples of anabolic agents

Answer 24

• romosozumab
• parathyroid hormone therapy

Question 25

MOA of romosozumab

Answer 25

Humainised mouse mAb -> inhibits sclerostin activity -> incr bone formation & decr bone resorption

Question 26

Administration of romosozumab

Answer 26

SC injection once a month

Question 27

When is romosozumab used

Answer 27

For women at high fracture risk / those who failed or intolerant to other therapies

Question 28

Example of Parathyroid hormone similars

Answer 28

teriparatide

Question 29

Administration of Parathyroid hormone similars

Answer 29

Once daily SC injection

Question 30

Max tx duration for parathyroid hormone similars

Answer 30

24 months

Question 31

IV zoledronate administration

Answer 31

Once a year

Question 32

Oral alendronate administration

Answer 32

Once a week

Question 33

Oral risedronate administration

Answer 33

Once a week or month