Osteoporosis Drugs - Fitz Flashcards
T-Score - what is it?
of SDs away from the average BMD of a middle age woman
T-Score - important ones
Above -1 = normal
-1 to -2.5 = osteopenia
Below -2.5 = osteoporosis
Each SD (T-score) correlates with what risk? BMD?
2x risk for vertebral fracture (10-20% BMD loss)
Preventing and treating osteoporosis requires what?
Adequate vitamin D and calcium
Calcium carbonate vs. Calcium citrate - Pros and Cons
Carbonate - Cheap, but needs stomach acid (meals)
Citrate - Expensive, but does not need stomach acid
Calcium absorption is only feasible with what else?
Adequate vitamin D3
Normal vitamin D requirement
When is it more? (6)
400-800 IU/day
Malabsorption, corticosteroids, anticonvulsants, loop diuretics, heparin, low sunlight exposure
Corticosteroids - which ones to worry about? (3)
Why is vitamin D requirement higher?
Prednisone, Methylprednisolone, Budesonide
Vitamin D is like a steroid, thus the steroid drugs compete for absorption and activation of vitamin D
A middle aged woman w/ COPD is being treated for increased severity w/ corticosteroids. What should be supplemented?
Vitamin D
Anticonvulsants - which ones to worry about? (2)
Why?
Carbamazepine, Phenytoin
Induces P450, thus increased metabolism of Vitamin D
A middle aged woman w/ epilepsy is being treated. What should be supplemented?
Vitamin D
Loop diuretics - why is the calcium requirement higher?
Causes calcium wasting
3 uses of bone density testing (1 important one here)
- Diagnose osteoporosis
- Predict fracture risk
- Monitor therapy - INITIATION OF GLUCOCORTICOIDS
Vitamin D activation requires what 3 things?
Sunlight, liver, kidney
PTH vs. calcitonin
PTH = increased bone resorption, increased Ca++ release Calcitonin = decreased bone resorption
Secondary causes of osteoporosis (via Ca++ or Vitamin D) (6)
MM, HyperPT, Hypogonadism, Liver disease, Kidney disease, Malabsorption
2 main classes of osteoporosis drugs
- Anti-resorption (osteoclast inhibitors)
- Anabolic (osteoblast activators)
Estrogen deficit leads to what?
Why?
Increased osteoclast activity
Estrogen normally causes apoptosis of osteoclasts to maintain the balance btwn blasts and clasts
A 55 y/o newly post-menopause female patient shows progressive bone weakening and is now below the fracture threshold. What should be suspected? Why?
Inadequate intake of Ca++ and Vitamin D (should not reach this level of bone weakness until old age)
Benefits to hormone (estradiol) replacement therapy for menopausal women?
- Increased bone health
- Decreased menopause symptoms
Risks to HRT for menopausal women?
- INCREASED RISK OF BREAST and UTERINE CANCERS
- Increased risk of heart attack, stroke, thrombosis
Treatment decisions for osteoporosis should be based on what?
FRACTURE RISK, age, BMD, other risk factors
A middle age woman recently started menopause, and her doctor suggests starting prophylactic therapy for osteoporosis. She chooses not to take HRT due to the cancer risks. What is the best alternative?
Raloxifene (selective estrogen-receptor modulators)
HRT vs. SERMs – actions in bone
BOTH are AGONISTS at ER in osteoclasts - cause increased osteoclast apoptosis to maintain the balance
