OP; OA; OM; Pagets Flashcards
Describe the pathophysiology of primary osteoporosis [2]
As age increases, get increased bone breakdown by osteoclasts + decreased bone formation by osteoblast
Oestrogen is key to the activity of bone cells with receptors are found on osteoblasts, osteocytes, and osteoclasts. Following menopause, its deficiency leads to an increased rate of age-related bone loss. This affects both the cancellous (spongy) and cortical (compact) bone.
Prolonged use of glucocorticoids can result in a reduced turnover state (less bone breakdown) though even here synthesis (bone formation) is affected more leading to a loss of bone mass.
State causes of secondary osteoporosis [+]
Endocrine:
- DM
- Cushings
- Hyperparathyroidism
- Hyperthyroidism
- Low testosterone
Malabsorptive
- IBD
- Coeliac
COPD
CKD
Chronic liver disease
Clinical features of osteoporosis? [2]
Pathological or fragility fractures:
- Vertebral compression fractures
- Appendicular fractures - proximal femur or distal radius following a fall: Neck of femur and Colles fractures
Label A-D
Normal = < 1
Osteopenia = -1 to -2.5
Osteoporosis = < -2.5
Severe Osteoporosis = Osteoporosis with one or more fragility fractures
How would you differentiate osteoporosis and osteomalacia?
- presentation [2]
- investigations [1]
osteomalacia may cause generalised bone pain, tenderness and myopathy
- low Ca and PO4 serum; high ALP and PTH
Describe the treatment algorithm for osteoporosis [4]
First line: Bisphosphonates
- oral alendronate or risedronate weekly oral
- zoledronic acid - yearly infusion
- MOA: interfering with the way osteoclasts attach to bone, reducing their activity and the reabsorption of bone.
Second line: Denosumab:
- monoclonal antibody agaisnt RANK ligand, inhibits osteoclasts
- SC every 6 months
- can be used for osteoporosis in post-menopausal women or OP In men
- can be used for patients on steroids
Raloxifene
- Raloxifene is approved for the treatment and prevention of osteoporosis in postmenopausal women
- selective oestrogen receptor modulator (SERM)
HRT: unopposed oestrogen or O&P
- Prevention of fracture in women at high risk. It is normally reserved for use in younger women as the side effect profile is better.
Clinical scenarios
- if a patient is deemed high-risk based on a QFracture or FRAX score they should have a DEXA scan to assess bone mineral density (BMD): if T-score of - 2.5 SD or below start bisphosphinates
- A postmenopausal woman, or a man age ≥50 has a symptomatic osteoporotic vertebral fracture: above
start treatment straight away - oral bisphosphonates are used first-line e.g. alendronate or risedronate
- following a fragility fracture in women ≥ 75 years, a DEXA scan is not necessary to diagnose osteoporosis and hence commence a bisphosphonate
The following are all used to treat osteoporosis when bisphosphonates are not suitable.
Which of the following acts increases the risk of osteonecrosis of the jaw and atypical femoral fractures?
Denosumab
Romosozumab
Teriparatide
Hormone replacement therapy
Raloxifene
Strontium ranelate
The following are all used to treat osteoporosis when bisphosphonates are not suitable.
Which of the following acts increases the risk of osteonecrosis of the jaw and atypical femoral fractures?
Denosumab
Romosozumab
Teriparatide
Hormone replacement therapy
Raloxifene
Strontium ranelate
Describe which side effects can occur because of bisphosphinates and how you would safety net them? [4]
Oral bisphosphonates are taken on an empty stomach with a full glass of water.
Afterwards, the patient should sit upright for 30 minutes before moving or eating to reduce the risk of reflux and oesophageal erosions.
Osteonecrosis of the external auditory canal and jaw. Need good dental care so should see dentist before and after treatment
Atypical fractures - the patient should be aware to present if they develop pain in their hip or thigh.
Which groups are bisphosphinates CI in? [3]
Severe renal impairment (renally excreted)
Hypocalcaemia
Upper GI disorders
Smokers and dental disease should be cautioned because of jaw necrosis risk
The following are all used to treat osteoporosis when bisphosphonates are not suitable.
Which of the following increases the risk of VTE?
Denosumab
Romosozumab
Teriparatide
Hormone replacement therapy
Raloxifene
Strontium ranelate
The following are all used to treat osteoporosis when bisphosphonates are not suitable.
Which of the following increases the risk of VTE?
Denosumab
Romosozumab
Teriparatide
Hormone replacement therapy
Raloxifene
Strontium ranelate
The following are all used to treat osteoporosis when bisphosphonates are not suitable.
Which of the following acts as parathyroid hormone?
Denosumab
Romosozumab
Teriparatide
Hormone replacement therapy
Raloxifene
Strontium ranelate
The following are all used to treat osteoporosis when bisphosphonates are not suitable.
Which of the following acts as parathyroid hormone?
Denosumab
Romosozumab
Teriparatide
Hormone replacement therapy
Raloxifene
Strontium ranelate
In which patient groups is raloxifene CI In? [1]
history of venous thromboembolism or if a patient has prolonged immobilisation due to risk of VTE
Name three side effects of raloxifene [3]
Side effects include hot flushes, vaginal dryness and leg cramps.
NB: Raloxifene is a selective oestrogen receptor modulato
Name two side effects of denosumab [2]
In which patient populations is it CI In? [3]
Side effects include cellulitis and hypocalcaemia
CI in hypocalcaemia and hypersensitivity and avoided in pregnancy.
heparin
Normal serum calcium, normal serum phosphate, normal ALP and normal PTH
SERM
Describe what is meant by an acute phase response when giving bisphosphinates [1]
Sometimes get acute phase response: fever, myalgia and arthralgia following administration