Drugs for Bone Flashcards
How much bone gets remodelled per year?
25% trabecular bone
3% cortical bone
Which bones are preferentially affected by bone remodelling?
femoral neck
vertebral bodies
T/F PTH affects both the activity of osteoblasts and osteoclasts
True
T/F Oestrogen preferentially targets osteoblasts
False, they decrease osteoclast activity
How does glucocorticoids affect bone cells?
increase osteoclast activity and decrease osteoblast activity
What is the clinical definition of osteoporosis?
reduction in bone mass more than 2.5 standard deviation below the norm for healthy 30 year old women
What’s osteopaenia
a less severe form of osteoporosis, only 1 to 2.5 standard deviation below the norm
How does osteoporosis cause back pain?
Target the vertebral body, reduction in the trabecular density, leading to microfractures and pain
What are the three antiresorptive agents?
bisphosphonates
selective oestrogen receptor modulator
RANK-L inhibitor
What is bisphosponate an analogue of?
analogue of pyrophosphate, but enzyme resistant
Describe the pharmacokinetic of bisphosponate
incorporated into bone matrix and accumulate at the site of bone mineralisation for long periods
ingested by osteoclasts to promote apoptosis and recruitment of more osteoclasts
How often do you administer bisphosponate? What’s the main side effect of this drug?
weekly
esophageal cancer
How does bisphosponate cause atypical fractures
It interrupts function of osteoclasts, hence the remodelling process of bone
How does oestrogen protect women from osteoporosis
promote osteoclast apoptosis
increase life span of osteoblasts and osteocytes
maintain bone mass
Why has oestrogen receptor modulators replaced direct oestrogen administration?
Oestrogen causes CVD and breast cancer
