Osteoporosis Flashcards
1
Q
bisphosphonates
A
oral: alendronate, risedronate (once weekly)
IV: zoledronic acid (once yearly)
MOA
- bind to hydroxappetite matrix
- when osteoclasts resorb section impregnated with bisphosphonate impairs ability to
- > form ruffled border
- > produce protons
- > adhere to bone surface
- also
- > decreases osteoclast progenitor development
- > decreases apoptosis of osteoblasts
SE
- GI irritation
- > reflux
- > esophagitis
- > ulcers
- transient hypocalcaemia
- > more common in IV
- > need to supplement vitamin d and calcium
- osteonecrosis of jaw
- > rare
- atypical femoral fracture
- zoledronic acute phase reaction (influenza like)
- > fever
- > myalgia/arthralgias
- caution in renal failure
2
Q
denosumab
A
subcut every 6 months
MOA
- monoclonal antibody to RANKL
- > prevents binding to RANK
- reduces
- > formation
- > function
- > survival of osteoclasts
SE
- most common
- > musculoskeletal pain
- > hypercholesterolaemia
- > cystitis
- spontaneous vertebral fractures
- > when stopped suddenly for more than 4 weeks
- hypocalcaemia
- serious side effects of anti-resorptive rare
3
Q
teriparatide
A
subcut once daily
MOA
- synthetic parathyroid hormone
- similar physiologic activity to PTH
- > stimulates osteoblast function
- > increases GI calcium absorption
- > increases renal reabsorption of calcium
SE
- well tolerated
- hypercalcaemia
- hypotension
- osteosarcoma
- > in rats
- > not demonstrated in humans (limited long term data)
4
Q
HRT
A
oestrodiol: oral (2mg) or transdermal equivalent
MOA
- marrow and bone cells express ER
- > loss of estrogen increases RANKL and decreases OPG
- > also reduced osteoblast lifespan and increased for osteoclasts
- evidence
- > reduces bone resorption
- > decreases BMD loss
- > reduces incidence of fractures
SE
- CHD and some cancers (eg breast) in long term use
- > lower risk when started in younger women
- > low absolute risk within 10 years menopause
- > lower risk in estrogen alone (vs combined)
- women with intact uterus
- > must also take progesteron
- > prevent endometrial hyperplasia
5
Q
SERMS
A
raloxifene
MOA
- bind with high affinity to oestrogen receptor
- > prevent bone loss
- > improve BMD
- decrease risk of vertebral fractures
- > in women more than 3 years post menopause
- > does not reduce non vertebral fractures
SE
- VTE
- stroke
- hot flushes
6
Q
vitamin D supplementation
A
D2 = ergocalciferol D3= cholecalciferol
MOA
- provitamin
- > active metabolite = 1,25 dihydroxyvitamin D
- stimules
- > calcium/phosphate absorption from small intestine
- > promotes secretion of calcium from bone to blood
- > promotes renale tubular phosphate resorption
- evidence
- > in trials with bisphosphonates or SERMs
- > fractures more common in vit D deficiency than replete
other sources
- sunlight
- fish oils
- fortified milk is significant dietary source
7
Q
non pharm osteoporosis
A
- adequate calcium and vitamin D
- exercise
- > both aerobic and resistance
- smoking cessation
- reduce alcohol intake
