Osteoporosis Flashcards
If crush fractures > long bone fractures in osteoporosis - which part of the bone is affected? vice versa?
If trabecular bone is aff ected, crush fractures of vertebrae are common (hence the ‘littleness’ of little old ladies and their dowager’s hump); if cortical bone is affected, long bone fractures are more likely, eg femoral neck:
Risk factors for osteoporosis?
parental history alcohol >4 units daily rheumatoid arthritis, BMI <19 prolonged immobility untreated menopause
Steroid use
Hyperthyroidism/ hyperparathyroidism/ hypercalciuria
Alcohol and tobacco use
Thin (BMI <18.5)
Testosterone low ((eg anti androgen ca prostate Tx).
Early Menopause
Renal or liver failure
Erosive/inflammatory bone disease (eg. myeloma or rheumatoid arthritis)
Dietary calcium reduced or malabsorption; diabetes mellitus type 1
Osteoporosis investigations?
DEXA scan
Urea & Electrolytes, Calcium, Phosphate, Alkaline Phosphatase, Thyroid Function.
Consider 25-OH Vitamin D if clinical evidence of osteomalacia.
Indications for a DEXA scan? When is DEXA not needed
NICE suggests DEXA if previous low-trauma fracture or for women ≥ 65yrs with one or more risk factors for osteoporosis, or younger if two or more.
prior to giving long-term prednisolone (eg >3 months at >5mg/d)
Men or women with osteopenia if low-trauma, non-vertebral fracture.
Bone and bone-remodelling disorders (eg parathyroid disorders, myeloma, HIV, esp. if on protease inhibitors).
DEXA is not needed pre-treatment for women over 75yrs if previous low-trauma
fracture
or ≥ 2 present of rheumatoid arthritis, alcohol excess, or positive family history.
How do steroids cause osteoporosis?
by promoting osteoclast bone resorption, reducing muscle mass, and reducing Ca2+
absorption from the gut.
Risk assessment tool for osteoporotic fracture?
FRAX, which is a WHO risk assessment
tool for estimating 10-yr risk of osteoporotic fracture in untreated patients
Lifestyle measure for osteoporosis Mx?
Advise adequate intake of calcium, vit D and protein, weight bearing physical exercise, smoking cessation, minimize excess alcohol intake
Pharmacological Mx of osteoporosis?
Bisophonates: 1st line: Alendronic acid - If intolerant, try etidronate or risedronate. -
What medication is used for pharmacological Mx of osteoporosis?
Bisphosphonates Calcium and vit D strontium ranelate HRT Raloxifene Teriparatide Calcitonin Testosterone Denosumab
How to take bisphosphonates? examples? SEs? Ix before commencing? CI? Alternative to oral bisphos?
Bisophonates: 1st line: Alendronic acid - If intolerant, try etidronate or risedronate.
Tell patient to swallow pills with 240ml water while remaining upright for >30min and wait 30min before eating or other drugs.
SE: photosensitivity
oesophageal reactions: oesophagitis, oesophageal ulcers
increased risk of atypical stress fractures of the proximal femoral shaft in patients taking alendronate
acute phase response: fever, myalgia and arthralgia may occur following administration
hypocalcaemia: due to reduced calcium efflux from bone. Usually clinically unimportant
Calcium, Vit D, renal function (eGFR>30)
CrCl>35 - if less use raloxefine
CI: Achalasia, strictures, ulcers - in which case
IV Zoledronate once a year (30min infusion) - optimise calcium and vit D - check teetch and post infusion Ca2+
Strontium ranelate SE? Use?
increased risk of CV events, thromboembolic events and serious skin reactions
should only be used in those with severe intolerance of other agents and without cardiovascular disease
HRT use? SE? Alternative?
no longer recommended for primary or secondary prevention of osteoporosis unless the woman is suffering from vasomotor symptoms
Increased risk of breast ca. and CV disease
raloxifene
Raloxifene MOA?
selective oestrogen receptor modulator (SERM) that acts similarly to
HRT, but with reduced breast cancer risk.
Teriparatide use? SE?
(recombinant PTH)
useful in those who suffer further fractures despite treatment with other agents. There is a potential increased risk of renal malignancy
Calcitonin use?
may reduce pain after a vertebral fracture
Denosumab MOA? Use? SEs? Admin?
a monoclonal Ab to RANK ligand
Inhibits ossteoclast formation, reduces bone resorption and increases BMD
Use if intolerant to other therapies eg. IV zoledronate + in those with impaired renal function
SEs: Skin infections, ONJ, stress fractures
Admin: Subcut once every 6 months - cannot be stopped abruptly –> rapid drop in BMD –> vertebral fracture
Common bone problems in elderly?
Osteoporosis and vit D deficiency. Also Paget’s disease of the bone, osteomalacia (clinically evident vitamin D deficiency), and Hyperparathyroidism.
o Bone pain or hypercalcaemia raises the suspicion of fractures, bony metastases or primary malignancy of the bone.
Phases of bone loss in women?
- occurs predominantly in trabecular bone and starting at menopause – menopause related bone loss
- After 4-8 years, the second phase exhibits a persistent, slower loss of both trabecular and cortical bone, and is mainly attributed to reduced bone formation - This is age related bone loss, which is the only phase that also happens in men.
Medications that contribute to bone loss?
SSRIs antiepileptics proton pump inhibitors glitazones long term heparin therapy aromatase inhibitors e.g. anastrozole Glucocorticoids Hormonal treatment (tamoxifen)
Define fragility fracture? Common fractures?
Fracture from falling from standing height, or lower at walking speed or slower
Vertebrae, proximal femur, wrist (distal radius, pelvis, ribs
Define alcohol excess for men and women
Alcohol excess for osteoporosis = >14 units in women, >21 units per week in men
