Osteoporosis Flashcards
What is osteoporosis?
Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures of the hip, spine and wrist.
3 million people in the UK have osteoporosis, there are an estimated 300,000 people who present to hospital every year with a fragility fracture.
What is osteoporosis?
Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures of the hip, spine and wrist.
3 million people in the UK have osteoporosis, there are an estimated 300,000 people who present to hospital every year with a fragility fracture.
What are the symptoms of OP?
Asymptomatic – often remains undiagnosed until a fragility fracture occurs.
Fragility fracture = a fracture that results from a mechanical force that would not ordinarily result in a fracture.
What are the three different cells in bone? Which one causes OP?
Three different types of cell in
bone:
Osteoblasts
Osteocytes
Osteoclasts
Increased osteoclast activity vs. osteoblast activity in osteoporosis
What are the modifiable, pharmaceutical and non modifiable risk factors?
Modifiable:
Bone mineral density
Low body weight
Falls
Smoking
Alcohol
Physical inactivity
Non-modifiable:
Sex
Age
Family history
Ethnicity
Previous fractures
Co-morbidities
Pharmacological:
Oral corticosteroids
Selective serotonin-reuptake inhibitors (SSRIs)
Anti-retroviral therapy
Thyroid medication
Proton-pump inhibitors (PPIs)
Long-term Depo-Provera
Gonadotropin-releasing hormone antagonists
Anticonvulsants
Aromatase inhibitors
Anti-diabetic drugs – pioglitazone
How is OP diagnosed?
Fracture risk calculators
https://qfracture.org/ https://frax.shef.ac.uk/FRAX/tool.aspx
DEXA scan is the most common way of measuring BMD – dual energy x-ray absorptiometry.
Bone mineral density (BMD) assessment:
Gives a T-score
Normal: T≥-1.0
Osteopenia: -2.5<T<-1.0
Osteoporosis: T≤-2.5
Established osteoporosis: T≤2.5 in the presence of ≥1 fragility fractures
What are the goals of therapy?
Reduction in fracture risk with an increase in BMD
Prevent future fractures
Maintain patient mobility
What vitamins are recommended to prevent and help manage OP?
Calcium and itamin D:
Recommended amounts per day - 700mg of calcium and 10micrograms of vitamin D.
A number of combination products available, most containing 1g of calcium and 400units (10micrograms) of vitamin D but preparations differ.
Used widely in practice for all patients with osteoporosis.
What is the 1st Pharmaceutical management?
alendronic acid
70mg once a week.
Avoid if GFR is <35mL/min.
risedronate
35mg once a week.
Avoid if GFR is <30mL/min.
Mode of action: inhibit bone resorption. Increase BMD by altering osteoclast activation and function which is responsible for the breakdown of bone.
Side-effects: upper GI effects, osteonecrosis of the jaw, osteonecrosis of external auditory canal, atypical femoral fractures.
Interactions: food, calcium, antacids, oral medications can interfere with absorption.
Cautions: active GI bleeding, duodenitis, dysphagia, gastritis, gastric ulcer in last year, surgery of upper GI tract, symptomatic oesophageal disease, peptic ulcers, upper GI disorders and renal impairment
Contraindications: pregnancy/breastfeeding, abnormalities of oesophagus and hypocalcaemia
MHRA warnings: atypical femoral fractures and osteonecrosis of the jaw and external auditory canal.
What is the second management
Cautions: active GI bleeding, duodenitis, dysphagia, gastritis, gastric ulcer in last year, surgery of upper GI tract, symptomatic oesophageal disease, peptic ulcers, upper GI disorders and renal impairment
Contraindications: pregnancy/breastfeeding, abnormalities of oesophagus and hypocalcaemia
MHRA warnings: atypical femoral fractures and osteonecrosis of the jaw and external auditory canal.
How do you counsel for oral preperations?
Counselling (oral preparations):
take at least 30 minutes before the first food, drink or medication of the day with a full glass of water (2hrs before or after at other times
Remain upright, do not lie down for at least 30 minutes after taking
Swallow the tablet whole – do not crush or chew.
Do not take at bedtime or if lying down.
Weekly dosing.
What is the second line?
Zoledronic acid:
Intravenous bisphosphonate – restricted to patients who cannot tolerate oral treatments or had poor response.
Long duration of action – 5mg once a year.
Most potent bisphosphonate licensed – can also be used to treat hypercalcaemia.
Avoid if renal function <35mL/min.
Duration of treatment – all bisphosphonates
5 year then review need for therapy – repeat DEX
If no new fractures – treatment holiday then restart for another 5 years if BMD <-2.5
Continue to 10yrs if vertebral fracture during treatment of T<-2.5
How does denosumab work and what are the contraindications?
Mode of action: human monoclonal antibody that targets and binds with high affinity and specificity to RANKL, preventing activation of its receptor, RANK, on the surface of osteoclast precursors and osteoclasts. This prevention inhibits osteoclast formation, function and survival, thereby decreasing bone resorption in cortical and trabecular bone.
Contraindication: hypocalcaemia
Dose: 60mg by subcutaneous injection every 6 months.
SMC restriction: BMD T-score <-2.5 and ≥-4.0 for whom oral bisphosphonates are unsuitable.
How does teriparatide work and what are the contraindications?
Mode of action: stimulation of bone formation by direct effects of osteoblasts, indirectly increasing the intestinal absorption of calcium and increasing the tubular re-absorption of calcium and excretion of phosphate by the kidneys.
Dose: 20microgram once a day by subcutaneous injection.
Used for severe osteoporosis – maximum duration of treatment is 2 years.
How does Raloxifene work and what are the contraindications?
Mode of action: selective oestrogen receptor modulator – reduces bone loss and increases bone density.
Reserved for 55–75-year-old women.
A significant reduction in the incidence of vertebral, but not hip fractures, has been demonstrated.
Dose: 60mg once a day.
