ic14, 18 osteoporosis Flashcards
What are the antiresorptive agents (5 points)
Alendronate, Risedronate
Zoledronic acid
Denosumab
Oestrogen, Raloxifene
Calcitonin
What are the anabolic agents
Romosozumab
Teriparatide
What is the MOA of PO bisphosphonates
Dose?
Slow bone growth by increasing osteoclast cell death
Alendronate: 70mg a week
Risedronate: 35mg a week
Unique adverse effects for oral vs IV bisphosphonates
Oral: abdominal pain, heartburn symptoms
IV: flu-like symptoms
Contraindications of bisphosphonates (5 points)
Abnormalities in oesophagus
Barrett’s oesophagus, gastric ulcers
GERD symptoms not counted, GERD must be quite severe
Cannot stand or sit upright ≥ 30 mins
Difficulty swallowing liquids
Severe renal impairment
< 30 ml/min for oral
< 35 ml/min for IV
Pregnancy and lactation
Counselling points of bisphosphonates eg. monitor SE (3 points)
Take with a glass of plain water, first thing in the morning and 30 minutes before breakfast
Do not lie down after taking
Observe for ONJ or atypical femoral fracture eg. pain in thigh, hip, groin while on treatment
Dose of Zoledronic acid
5mg IV infusion over 30 minutes, once a year
Duration of therapy for Alendronic acid VS Zoledronic acid
Alendronic acid
5 years for low # risk (FRAX major < 20%, hip < 3%)
10 years for high # risk (FRAX major > 20% or hip >3%)
Zoledronic acid
3 years for low # risk (FRAX major < 20% or hip < 3%)
6 years for high # risk (FRAX major > 20% or hip >3%)
How to diagnose osteoporosis (2 points)
1) History of fragility fracture
Occur spontaneously or from minor trauma
2) BMD measurement using DXA hip or DXA spine
T score compares patient to BMD of young adult, so more deviation means osteopenia or osteoporosis
Osteoporosis: T score ≤ -2.5
Osteopenia: T score: -1 to -2.5
Normal bone density: T score ≥ -1
What is Z score for, what is the cut off
Compares BMD against expected BMD of patient’s age and gender
Not used for diagnosis
If ≤ -2, suggests coexisting problems eg. glucocorticoid therapy, alcoholism that can contribute to osteoporosis
When to start osteoporosis treatment
1) Have fragility fracture, treat after recovery
2) Without fragility fracture, but osteoporotic (DXA BMD T score ≤ -2.5)
3) Osteopenic (DXA -2.5 to -1), but high fracture risk
Fracture Risk Assessment Tool (FRAX) score is high
FRAX: calculate 10 year probability of fracture
Major osteoporotic #: ≥ 20%
Hip #: ≥ 3%
What should be done before starting osteoporosis treatment
Check serum Ca2+ and Vit D levels before starting treatment
Vit D: between 30-50 ng/ml
Give Ca2+ and Vit D supplementation during treatment
Give Ca2+ 2 hours after Alendronic acid
Can take first dose of Ca2+ after lunch to ensure sufficient separation
Monitoring of bisphosphonate treatment
When to restart treatment?
Check BMD DXA T score every 2 years during the 3 or 5 year treatment course, if BMD improves then continue bisphosphonate treatment until 3 or 5 years
Check BMD after 2 years of stopping, If BMD decreases >5% or patient meets treatment criteria again
What is Denosumab? and the MOA
RANKL inhibitor
prevent development of osteoclasts
When is Denosumab indicated?
2nd line, administered for poor renal function (CrCl < 30ml/min)
