ic18 osteoporosis management Flashcards
what are drug causes of osteoporosis
1) glucocorticoids
2) cyclosporine
3) anticonvulsants: phenobarbital/ phenytoin
4) aromatase inhibitor
5) GnRH agonists/antagonists
6) Heparin
7) Cancer chemotherapy
what are the clincal manifestations of osteoporosis
usually asymptomatic until fragility fracture of
- spine
- hip, wrist, humerus, pelvis
fragility fracture = occurs spontaneously or from minor trauma not normally resulting in fractures
how to monitor for spine fragility fracture
vertebral compression = height loss or bending over (kyphosis0
which individuals should be assessed for osteoporosis?
post menopausal women and
>65yo men
what are the risk factors for osteoporosis
x12
family history
previous fragility fracture
aging
low body weight
height loss >2cm in 3 yrs
early menopause (≤45yo)
low calcium intake <500mg/day
excessive alcohol intake >2u/day
smoking
prolonged immobility
hix of falls
diseases lowering bone density or increasing frx risk (DM, inflammatory rheumatic diseases)…
any of these risk factors = should definitely go for screening
BMD using DXA hip and/or spine and risk
T score ≤2.5 SD = osteoporosis
-1 to -2.5 = osteopenia
≥ -1 = normal bone density
note that spine DXA may not be accurate for elderly due to higher likelihood of spine degeneration with age
BMD using DXA z score what is it?
compares against expected BMD of people in the same age/sex
- z score ≤ -2 SD = possible underlying/coexsiting problems eg glucocorticoid/alcoholism
what are some commonly indicated tests TO rule out secondary causes of bone loss (and when to initiate)
if z score ≤-2, then
1) creatinine = any CKD-MBD?
2) FBC = check for malignancy/malabsorption
3) corrected calcium = increase may be due to hyperparathyroidism/malignancy, decrease may be due to vitDdef/malabsorption
4) 25(OH)D = test baseline, aim for >20ng/mL
other tests for z score ≤ -2
1) thyroid stimulating hormone (hyperthyroid?),
2) ESR (rheumatic disease?),
3) ALP (liver disease, recent fracture, paget disease),
4) serum phosphate (vit D def or renal phosphate wasting),
5) spot urine calcium/creatinine ratio (idiopathic hypercalciuria),
6) serum total testosterone (hypergonadism)
what is FRAX score and how to use
10 year probability for
major osteoporotic fracture (≥20%)
hip fracture (≥3%)
- major osteoporotic bones include: pelvis, femoral, tibial
treatment decision for osteoporosis
Choice of drugs
* 1) bed bound: consider SC/IV agents. (zolendronic for biphosphonates, denosumab).
* 2) oesophageal or gastric abnormalities (not GERD but more serious) = avoid PO biphosphonates.
* 3) hypocalcaemia: do not start until patient corrected.
* 4) renal impairment: (<30) avoid biphosphonates, consider denosumab.
What other agents to add?
* calcium and vitamin D supplementation. Take 2h apart.
What other considerations?
* Hypocalcaemia = do not start until calcium levels are corrected.
* Hypersensitivity.
* Plans for invasive dental procedures = complete first
* Has patient recovered from fragility fracture? = initiate 2 weeks post fracture.
zoledronic acid dose
5mg once a year as 15min infusion
risendronate dose
35 mg per week
alendronate dose
70mg per week
c/i zoledronic
hypocalcaemia and crcl<35
