Drugs Used to Treat Bone Disorders Flashcards
Which type of bone is preferentially remodelled, trabecular or compact?
Trabecular
What is the major cause of hyperphosphataemia?
Renal failure
What is the pathophysiology of osteoporosis at a cellular level?
Increase activity and life span of osteoclasts
Decreased life span of osteoblasts and osteocytes
= Larger and deeper resorption cavities in bone = more fragile bone
How are biphosphonates administered?
Taken on a weekly basis
Which two bones are preferentially effected by pathological remodelling?
Head of femur
Vertebral bodies
What is the effect of oestrogen on bone cells?
Decreases the activity of osteoclasts
What is the suggested long term treatment regiment for osteoporosis in females?
Start with HRT
Then Raloxifene + Bisphosphonates + PTH + Ca + Vitamin D + RANK-L inhibitors
What stimulates osteoblasts to express RANK-L?
Calcitriol
PTH
How does oestrogen therapy effect bone mass?
Maintains bone mass
Slows bone breakdown
How can PTH therapy work to reduce bone density loss?
Because PTH treatment acutely increase osteoblast activity (whilst continuous high exposure of PTH favours bone catabolism)
What is an advantage of SERMs?
It is an antagonist of oestrogen receptors in mammary tissue therefore doesn’t carry a breast cancer risk
What is the mechanism of action of bisphosphonates?
They are absorbed into bone
Osteoclasts that ingest them are inhibited and apoptosis is promoted
What type of drug is denosumab?
A monoclonal antibody RANK-L inhibitor therefore blocks the activation of osteoclasts
What type of drug is alendronate?
Bisphosphonate
What is the specific definition of osteoporosis?
A reduction of bone mass by greater than 2.5 standard deviations for a 30 year old female
