Osteoporosis Flashcards
When do men and women begin to lose bone mass?
30s-40s (reduced bone formation)
What effect does Estrogen deficiency have during menopause
less estrogen increases osteoclast activity increasing bone resorption more than formation
Osteoblast function
osteoblasts “b”uild bone!
Name some drugs that cause osteoporosis
- Systemic corticosteroids
- Thyroid replacement
- Antiepileptic drugs (ex. phenytoin and phenobarbital)
Risk factors for fracture
- age
- history of fracture
- rheumatoid arthritis
- excessive alcohol
- smoking
- inflammatory bowel disease, hypogonadism
FRAX tool
- created by WHO
- uses risk factors to predict probability of fracture in next 10 years
Garvan calculator
- uses 4 risk factors (age, sex, low-trauma fracture, falls)
- Calculates 5 and 10 year risk of hip fracture and major bone fx
[corrects some disadvantages of FRAX)
What is osteoporosis diagnosis based on?
- Low trauma fracture
or
- Central hip and/or spine DXA using WHO T-score thresholds
Osteopenia T score
T-score between -1 and -2.5
low bone mass
Osteoporosis T score
T-score -2.5 or less
Who does the T score apply to?
- postmenopausal women
- perimenopausal women
- men 50+
Who does the Z score apply to?
diagnosis of osteoporosis in
- children
- premenopausal women
- men under 50
What does the Z-score have to be to diagnose osteoporosis in children, premenopausal women, and men under 50?
Z score of less than 2 (in combination with other risk factors or fracture)
What is the antiresorptive therapy of choice along with calcium and vitamin D?
Bisphosphonates
What does Vitamin D increase intestinal absorption of?
calcium and phosphorous
What is the recommended dietary allowances of calcium for adults 19-50 years old?
1000-2,500mg
What is the recommended dietary allowance of vitamin D for ages 9 to 70?
600- 4,000mg
Which form of calcium is better tolerated
Calcium citrate (but, more expensive)
calcium carbonate (gas, bloating, constipation)
Adverse effects of calcium supplementation
- Hypophosphotemia
2. Hypercalcemia
How do you treat Vitamin D deficiency
50,000iu weekly for 8-12 weeks
Who are bisphosphonates indicated for
- postmenopausal female
- men
- glucocorticoid-induced osteoporosis
Intravenous and oral ibandronate is indicated only for _______
postmenopausal women
Bisphosphonate: MOA
inhibit bone resorption:
-decreased osteoclast maturation, number, recruitment, and life span
Bisphosphonate 1/2 life
up to 10 years
What is important to remember about taking oral Alendronate (Fosamax)
Take in the morning on an empty stomach and don’t eat or lie down for at least 30 minutes. Avoid taking with calcium and vitamin D
What is important to remember about oral Ibandronate (Boniva)?
Take in the morning on an empty stomach and don’t eat for at least 60 minutes
What is important to remember about Risedronate (Atelvia)?
Immediate release like Alendronate (take on empty stomach and wait 30 min)
Delayed release- take immediately following breakfast
How is zoledronic acid given?
IV once a year
What can be given before infusion with zoledronic acid to decrease infusion reactions?
acetaminophen
When is zoledronic acid contraindicated?
if CrCl is <35 mL/min
ADEs of oral bisphosphonates
nausea
dyspepsia
ADEs of IV bisphosphonates
transient flu-like illness
What are 2 rare and adverse effect of bisphosphonates?
- osteonecrosis of the jaw
2. Subtrochanteric femoral fracture
Bisphosphonate contraindications
- Creatinine clearance of <30-35mL/min
- Esophageal abnormalities
- Pregnancy
Who can be considered eligible for a “drug holiday” on bisphosphonates?
- Women without evidence of a low-trauma fracture
- If good response to treatment
- If BMD increasing to >-2 (getting into osteopenic range)
When can a drug holiday be considered?
If low risk can consider stopping after 5 years of treatment
If high risk for fracture (T-score below -3.5, consider alendronate for up to 10 years
At what age can calcitonin be used?
at least 5 years past menopause
What form does calcitonin come in?
nasal spray
refrigerate until opening, then use at room temp
Raloxifene (Evista) and bazedoxifene (Duavee) drug class
Estrogen Agonist/Antagonist
What is Teriparatide
recombinant pieces of PTH
Who is Teriparatide indicated for?
Very low bone density with T score
What is important for the first dose of teriparatide?
patient needs to be sitting or lying down as first dose can cause orthostatic hypotension
Teriparatide dosing?
daily subcutaneous injection
Abaloparatide
synthetic analog of human PTH
acts as an anabolic agent to stimuate bone formation
Who is abaloparatide used for?
high-risk postmenopausal osteoporosis
Denosumab: MOA
RANKL inhibitor that inhibits osteoclatogenesis and increases osteoclast apoptosis
Denosumab: ADEs
- back, extremity, and musculoskeletal pain
- increased cholesterol
- cystitis
When is calcitonin used?
LAST RESORT
First line therapy for osteoporosis
- Alendronate
- Risedronate
- Zoledronic acid
- Denosumab
What causes Osteomalacia?
Undermineralized bone from prolonged vitamin D deficiency
Osteomalacia treatment?
Vitamin D
What labs may be seen in osteomalacia
elevated alkaline phosphatase
hypocalcemia
