Osteopenia & Osteoporosis Flashcards
Age-related decrease in bone mass secondary to uncoupling of osteoclast-osteoblast activity defines what condition?
Osteopenia and osteoporosis
What is the most common osteoporotic fracture?
1) Vertebral fx; 700,000.yr
2) Hip fx; 300,000/yr
3) wrist fx; 200,000/yr
What medications are a/w increased risk of osteoporotic fx?
1) oral corticosteroids
2) androgen-deprivation therapy
3) aromatase inhibitors
4) protease inhibitors
5) selective serotonin reuptake inhibitors
6) prolactin-raising antiepileptic agents (e.g. phenytoin)
7) cytotoxic agents
What type of THA prosthesis increases risk of fragility fracture?
Constrained liners; redistributes forces through pelvic ring
What is the biggest risk factor for vertebral fragility fracture?
history of 1 vertebral fracture results in 5 fold increased risk of 2nd vertebral fracture and 5 fold increased risk of hip fracture
What affect do vertebral and hip fractures have on mortality?
Vertebral fracture has 5-yr 15% increased mortality
Hip fracture has 20% increase mortality in first year only
According to FRAX guidelines for risk of fragility fracture, when should anti resorptive therapy be started?
one of the following criteria: (1) they have a prior hip or vertebral fracture, (2) they have a T score -2.5 or less at the femoral neck or spine, (3) they have a T score between -1.0 and -2.5 at the femoral neck or spine AND a 10-year risk of hip fracture greater than 3% or 10-year risk of major osteoporosis-related fracture greater than 20%.
What lab should be ordered and followed in fragility fractures?
25-OH Vit D
51% are below threshold level of 15ng/mL
What is the MOA of bisphosphonates?
decrease osteoclastic bone resorption, flattening of osteoclast ruffled border (calcitonin also flattens border) and increased osteoclast apoptosis
What is a rare complication of IV bisphosphonates that is absent in oral bisphosphonates?
Osteonecrosis of the jaw
What is the daily recommended amount of Ca and Vit D in pts over 50?
Age >50 yrs- 1200 to 1500 mg/d calcium
800-1,000 IUs Vit. D
What is the MOA of Non-nitrogen containing Bisphosphonates?
Produce toxic ATP analog
e.g etidronate, clodronate, tiludronate
What is the MOA of nitrogen containing bisphosphonates?
Inhibit farnesyl pyrophosphate synthase (mevalonate pathway)
pamidronate, alendronate (Fosamax), risedronate (Actonel), zolendronate (Reclast), ibandronate (Boniva)
What is the MOA of deonsumab (Prolia)?
Monoclonal Ig2 against RANKL (inhibits binding of RANKL to RANK, like osteoprotegerin)
Indicated in post menopausal women at risk for fragility fracture
What is the MOA of teriperitide (Forteo)?
Receptors on osteoblasts (activates osteoblasts) and renal tubule cells, also stimulates intestinal absorption Ca and PO4
