Management of Osteoporosis Flashcards
What is the difference between osteoblasts & osteoclasts?
Osteoblasts: cells responsible for bone formation
Osteoclasts: cells responsible for bone shedding
What happens to the balance of osteoblasts & osteoclasts in osteoporosis?
Osteoclast activity > osteoblast activity.
More bone is shedded then formed.
Which specific class of drug can cause osteoporosis?
Corticosteroids, because they increase osteoclast activity.
Why are patients with osteoporosis more prone to fractures?
Because the thinning of their bone results in less bone density = more prone to fractures
Why are menopausal women more prone to osteoporosis?
Because in menopause you lose oestrogen, which normally helps in maintaining bone function.
What are the risk factors of osteporosis?
- Increasing age
- Females
- Early menopause
- Smoking/alcohol
- White & Asian people
- Drugs that increase metabolism of vit. D (phenytoin, PPIs)
- Fragile, low weight individuals
What are the symptoms of osteoporosis?
Symptoms are the result of fractures from osteoporosis. They can occur at 3 sights in the spine.
What is a Colles Fracture?
Wrist fracture.
What is kyphosis?
Curvature of the spine, making you lose height.
What 3 investigations are performed to diagnose osteoporosis?
- DXA scan (dual energy x-ray) - measures real bone density. It is a negative number.
- T score - is the measurement of the DXA scan
- X-ray
What is the T score of someone with osteoporosis?
Less than -2.5 = osteoporosis
What is Bindex in osteoporosis?
It is a portable ultrasound device used to investigate the density of the bone using sound waves.
At what age should someone be assessed for a fracture risk?
Women >65yrs + presence of risk factors
Men >75 yrs + presence of risk factors
What main factors should you focus on when assessing a person for osteoporosis?
- Their gender (females more prone)
- Age
- Weight - are they frail?
- Any medications they are taking
- Menopause
When should you assess a patient <40years old for osteoporosis?
- If they have premature menopause
- Taking corticosteroids
- History of falls/fractures
What is FRAX (or Qfracture) in osteoporosis?
It is a tool/questionnaire to assess the risk of a fracture of a person within the next 10 years
- Remember FRAX only screens for osteoporosis, nothing else
What risk factors are considered when using FRAX?
- Age/sex
- BMI
- Previous fractures
- Current glucocorticoid treatment
- Smoking/alcohol
- Any secondary causes
What is the advantage of having IV bisphosphonate?
It is only given once a year (if the risk of a fracture is >10%)
What are some non-drug therapies for osteoporosis?
- Regular exercise
- Vitamin D & Ca2+ intake
- Stop smoking/alcohol
- Maintain BMI
Even if someone has a 1% risk of a fracture, are they still treated?
Yes to prevent future fractures.
Which supplement excess can cause osteoporosis?
Ca2+
What is the main class of drug given as treatment for osteoporosis?
Bisphosphonates
What is the mode of action of bisphosphonates?
- They bind to the crystal structure of the bone & decrease osteoclast activity
- This prevents shedding of Ca2+ from the bone
- Osteoclasts undergo apoptosis
Which 2 bisphosphonate drugs are in an IV infusion?
- Ibandronic acid
2. Zoledronic acid
Why cant bisphosphonates (e.g. alendronic acid, or risedronate sodium) be taken with Ca2+ supplements/food/drink?
Because they would bind to the Ca2+ from the tablet/food/drink & not on the bone = no efficacy
Why should alendronic acid be taken with a full glass of water, standing up?
Because it can cause oesophageal reactions if the tablet does not go down fully.
What is the dose of alendronic acid, and risedronate sodium?
Alendronic acid:
70mg weekly , or 10mg daily
Risedronate sodium:
5mg daily, or 35mg weekly
What condition are patients taking IV bisphosphonates more prone to?
Osteonecrosis of the jaw.
Good dental/oral hygiene is therefore needed.
How many years should a patients bisphosphonate use be reviewed?
Should be reviewed every 5 years.
Zoledronic acid reviewed every 3 years
How long is the holiday treatment period for alendronic acid, risedronate sodium, and zolendronic acid?
Alendronic acid: 2 years
Risedronate sodium: 1 year
Zolendronic acid: 3 years
- Remember it like 1R, 2A, 3Z (RAZ)
What ear condition can occur due to long-term usage of bisphosphonate?
Osteonecrosis of the external auditory canal.
What type of drug is denosumab, & what is its mode of action?
It is a monoclonal antibody.
It prevents RANKL from binding to RANK receptors on osteoclasts, so osteoclasts are not activated = no shedding occurs
What is the dose for denosumab in osteoporosis?
60mg every 6 months via subcutaneous injection (Prolia)
How does estrogen & teriparatide work?
They bind to osteoblasts to increasing bone formation
When is denusomab given?
If the patient cannot take any other bisphosphonate, AND have a high risk of fracture.
What 4 major things do you have to consider before choosing the right treatment for a patient with osteoporosis?
- History of hip fractures
- Alcohol intake
- Rheumatoid arthritis
- Age
- (other risk factors if applicable)
What 2 risks can occur while taking denosumab 60mg?
- Osteonecrosis of the jaw - more common in cancer treatment
- Hypocalcaemia
What risk factors can increase a patients chance of having osteonecrosis of the jaw?
- Smoking
- Advanced cancer
- Poor oral hygiene
- Previous treatment with bisphosphonates
- Old age
What should always be measured before each administration of denosumab?
Ca2+ levels.
What are the symptoms of hypocalcaemia?
- Muscle spams
- Tingling in fingers/toes/around mouth
- Numbness
- Cramps
What is an example of a SERM, and what is its mode of action?
Raloxifene. It activates estrogen receptors on osteoblasts to induce bone formation.
What is the mechanism of action of strontium ranelate?
It stimulates bone formation & reduces bone shedding.
When is strontium ranelate used?
Only if previous treatments have not worked, & only in specialist care.
What is the dosing of strontium ranelate?
2g OD in 30mL water, at bedtime.
- Avoid Ca2+ containing products too
When should the use of strontium ranelate be stopped immediately?
If a rash/severe allergic reaction occurs.
Assess the CV risk of the patient since it can increase CV risk too.
When is HRT used as treatment for osteoporosis?
When all other treatments have failed.
It is also only used for premature menopausal women, & stopped at the natural age of menopause (50 years old)
What risks increase while taking HRT?
CVD (clotting), stroke, and breast cancer
What can HRT also be used for besides treatment?
Prophylaxis of postmenopausal osteoporosis (those with high risk)
When is teriparatide given?
As a secondary prevention in fragile women who have osteoporosis to reduce their risk of a fracture.
- Used in those very high risk
- Use it limited due to costs
What is the dosing of teriparatide?
20mcg daily via subcutaneous injection (for 2 years)
What makes up teriparatide?
It is a fragment of the parathyroid hormone (inducing growth factors to make new bone)
How does romosozumab work?
It is a monoclonal antibody which binds to sclerostin in osteocytes.
Sclerostin inhibits bone formation, so blocking this = bone remains
What is the dosing of romosozumab?
210mg once a month for 1 year +
vit C/D also taken as 105mg injections
Besides osteoporosis, which patients should be considered for bone protective therapy?
Patients >70years old taking high levels of corticosteroids (>7.5mg/day prednisolone)
What are the 2 first line treatment options for osteoporosis in men?
Alendronic acid & risedronate
What are the alternative treatment options for osteoporosis in men?
Zoledronic acid, or denosumab (can also consider strontium ranelate or teriparatide)
