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 considerations 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 30min infusion
risendronate dose
35 mg per week
alendronate dose
70mg per week
c/i zoledronic
hypocalcaemia and crcl<35
c/i risendronate and alendronate
Oesophageal or gastric abnormalities
(e.g. gastric ulcers, achalasia, uncontrolled GORD, erosive esophagitis)
Inability to stand/sit upright for ≥30min
aspiration risk (difficulty swallowing liquids)
crcl <30
hypocalcaemia
treatment duration for biphosphonates
5 years for PO, 3 years for IV
check in 2 years, if BMD DECREASE by > 4-5% then restart…
dosing for denosumab
60mg every 6 months SUBCUTANEOUSLY
C/I DENOSUMAB
HYPOCALCAEMIA
treatment duration for denosumab
indefinite
risk of vertebral fracture if missed dose or discontinue
SE for biphosphonate
ONJ and atypical femoral fracture (monitor for thigh hip or groin pain)
other SE for denosumab
risk of serious infections:
diverticulitis, pneumonia, cellulitis…..
risk factors for ONJ
invasive dental procedures
hx of cancer or radiotherapy
concomitant therapy with angiogenesis inhibitors, chemotherapy, corticosteroids
comorbid disorders (anemia, coagulopahty, infection, pre-existing dental/periodontal disease
counselling for oNJ
MAINTAIN GOOD DENTAL HYGIENE
AVOID INVASIVE DENTAL PROCEDURES WHILE ON TX
SMOKING CESSATION
what should calcium and vit d levels be before starting biphosphonates and …
25(OH)vitD should be ≥20-30ng/mL or 50-75NMOL/L (but less than 50 or 125-250)
what to monitor during therapy
serum creatinine
serum calcium
serum 25ohvitD
what should calcium supplementation be and when to give
1000mg/day of elemental caclium for >50yo
or
800mg/day for 19-50yo
to be given esp if paitnet takes less than 700mg dietary calcium per day
DDI calcium
PPI and fibre decreases calcium alsorption
calcium decrease absorption of
- tetracyclines, fluroquinolones
- iron
- thyroid supplements
benefits of calcium intake
may help to increase BMD (small)
potential side effects of dietary calcium
GI side effects = constipation
possible CVS risk
increased risk of nephrolithiasis
how much vit D to take
51-70yo = 600IU/day
>70yo = 800IU/day
whtat and when to give vit d
give 800iu per day cholecalciferol
ddi vit d
rifampin
anticonvulsants (phenytoin, val, cbz)
cholestyramine
orlistat
aluminium products
benefits of vit d intake?
may reduces falls and possibly risk of fractures
nonphx measures
advise on weight bearing, muscle strengthening or balance exercises eg walking, elastic band exercises, taichi
atleast 30min 2-3 times per week
counselling points for OSTEOPOROSIS
EDUCATE on fall risk, home safety, footwear
- consider meds that may cause drowsiness or sedation…
stop smoking, limit alcohol (max 2units/day) and caffeine (max 2 cups)
dose of teriparatide and ci
SC 20ug OD x2 years
crcl<30
paget disease, he of bone radiation
hypercalcaemia
dose and ci of raloxifene (and other considerations)
60mg OD
ci: crcl<30, hx of vte, hepatic and severe renal
for women w no hot flushes
consider HRT if hot flushes are severe
counselling for zoledronic acid
ensure adequate hydration before infusion
