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Flashcards in Drugs Affecting Bone Deck (30):
1

Osteoid is made up by

Collagen, cytokines and growth factors

2

how much bone is remodelled per year in adults?

25% trabecular
3% cortical

3

osteoporosis occurs at sites of high [trabecular bone]

Neck of femur
Vertebrae

4

the reabsorption of bone causes the release of cytokines from the mineralised osteoid such as ---1--- and their function is to activate ----2---- and induce ---3---

1 IGF and TGF-ß
2 Osteoblast
3 Bone deposition

5

hormones that decrease osteoclast activity include?

oestrogen, calcitonin

6

hormones that increase osteoblast activity?

PTH, embedded cytokines, calcitonin

7

some of the functions of calcitriol include?

Increases intestinal CA+2 absorption
Decreases renal excretion
Increases osteoclast activity

8

some of the functions of PTH include?

increases osteoblast production of RANKL
Decreases osteoblast production of Osteoprotegerin
Increases kidney hydroxylation of vitamin D to its active form
reduces renal Ca+2 excretion

9

some of the functions of calcitonin include?

decreases osteoclast activity (by inducing OPG production)
increases bone deposition
decreases Ca reabsorption from the kidney

10

What is the definition of osteoporosis?

reduction in bone mass of more than 2.5 SD bellow the norm for healthy 30yo women
[loss of both cells and matrix]

11

what is the definition os osteopaenia?

reduction in bone mass 1-2.5 SD bellow the norm for healthy 30yo women

12

what are some of the changes observed in osteoporosis?

trabecular thinning
loss of trabecular connectivity

13

what are the main two types of drugs used in bone disorders?

Block osteoclast Activity (Antiresorptive Agents)
Boost osteoblast activity (Bone Anabolic Agents)

14

Block osteoclast Activity (Antiresorptive Agents) include

*Biphosphonates
Selective oestrogen receptor modulators
RANKL inhibitors

15

Boost osteoblast activity (Bone Anabolic Agents) include

Vitamin D analogues
PTH
Ca+2
Vitamin D

16

how do biphosphonates work? [alendronate]

Deposited into bone by osteoblasts
Released and phagocytosed by osteoclast
induces apoptosis of the osteoclast and inhibits their recruitment

17

Biphosphonates are

Enzyme Resistant Analogues of pyrophosphate (P-O-P)

18

how often do biphosphonates need to be administered?

once a week but they persist in bone for a long time
patient must walk or be sited after ingestion (risk of oesophagitis --> lead to increased risk of oesophageal cancer if taken for more than 3 years)
once taken it is fo'life yo

19

how does oestrogen work?

Decreases reabsorption
Decreases differentiation and proliferation of osteoclasts
Promotes osteoclast apoptosis

20

oestrogen analogues increase bone mass T/F

F, just maintenance of left behind and slows bone loss

21

What medication is given instead of oestrogen (as it has a risk for cardiovascular complications and breast cancer?)

Selective Oestrogen Receptor Modulators (SERMs) [Raloxifene]

22

mechanism of action of SERMs

Agonist at cardiovascular tissue and bone
Antagonist at mammary tissue and uterus

23

Mechanism of action of RANKL inhibitors [denosumab]

binds to Receptor Activator of Nuclear Kappa Beta ligand (RANKL) to block its binding to RANK on osteoclasts (necessary for differentiation, survival and activity)

24

RANKL inhibitors are able to

decrease bone turnover and increase bone density

25

PTH activity on bone depends on ---1-- in what way

[] and periodicity of exposure
Low dosages causes anabolism of bone
High prolonged doses causes catabolism of bone

26

Oral calcium salts has as a side-effect

GIT disturbances

27

Vitamin D is used in the treatment of

deficiency of Vitamin D
Hypoparathyroidism
Chronic Renal Disease

28

what main forms of vitamin D are available? and how is it used?

Vit D2 [ergocalciferol] (for liver conversion)
Calcitriol
--> prophylactically

29

is treatment recommended in women with osteopenia?

no, except if there are fractures

30

What si the recommended treatment for osteoporosis?

HRT (between 50-60)
>60 Raloxifene and Biphosphonates Ca+ and VitD