Osteoporosis

Question 0

Alendronate, Risedronate, Ibandronate

Answer 0

Bisphosphonates –l osteoclast-mediated bone reabsorption
Use: #1 for Osteoporosis, Paget’s disease
* decrease spine AND hip fractures 50%!
* t1/2 = 10 yrs! (effects last BEYOND stop taking)
SE: osteonecrosis of jaw, acid reflux/esophageal erosion (GI), headache, muscle pain, atyp. femur fractures w/ prolonged use

Question 1

Bisphosphonates

Answer 1

synthetic pyrophosphate analogs, bind to bone hydroxyapatite –> inhibit osteoclast-mediated bone reabsorption
* take w/ water & don’t lay down for 30 min to prevent acid reflux/esophageal erosion.

Question 2

Pamidronate, Zoledronic Acid

Answer 2

IV only bisphosphonates, –l osteoclast-mediated bone reabsorption
Use: Paget’s Disease, hypercalcemia of malignancy
* decrease spine AND hip fractures 50%!
* t1/2 = 10 yrs! (effects last BEYOND stop taking)
SE: osteonecrosis of jaw, muscle pain/flu-like rxn
atyp. femur fractures w/ prolonged use

Question 3

Raloxifene

Answer 3

“SERM” = selective estrogen R modulator (estrogen agonist @ bone, but antagonist @ breast & uterus)
Use: Osteoporosis *weak, only prevent spine fractures (not hip)
SE: hot flashes, venous thromboembolism

Question 4

Calcitonin

Answer 4

activates calcitonin R (GPCR) on osteoclasts => decrease bone resorption
Use: post-menopausal osteoporosis, Paget’s, hypercalcemia
*weak, only prevent spine fractures (not hip).
SE: nasal spray –> rhinitis; injection –> nausea, diarrhea, flushing

Question 5

Denosumab

Answer 5

humanized monoclonal Ab to RANK-L
=> block RANK (receptor) activation on osteoclasts
Use: osteoporosis (VERY effective!)
- 70% less spine fractures, 40% less hip fractures
SE: hypocalcemia & infections (esp if pre-existing), dermatitis, eczema, jaw osteonecrosis, muscle pain, atypical femur fractures

Question 6

Teriparatide

Answer 6

hPTH => increase bone remodeling rate/stim. bone formation
(by prolong life of osteoblasts & osteocytes)
Use: severe osteoporosis (postmenopausal or M)
SE: HyperCa+ (in blood & urine), leg cramps, dizziness, & high serum uric acid (–> gout)
* short-term use only! (osteosarcoma risk)*

Question 7

Strontium

Answer 7

decrease bone reasorption
Use: Osteoporosis
SE: nausea, diarrhea, headache
* not available in USA yet (only Europe)*