Osteoporosis

Question 1

Vit D: Cholecalciferol

Ergocalciferol, Calcitriol

Answer 1

Increases activity of osteoclasts & osteoblasts,
Increases bone remodeling (osteocytic osteolysis),
Increase mineralization through increased intestinal Ca+ absorption, renal Ca+ & phosphate reabsorption, decrease PTH synthesis
For osteoporosis, osteomalacia, renal failure, malabsorption, psoriasis
Adverse Effects: hypercalcemia, kidney stones, hypercalciuria, calcification of soft tissues, increased risk of prostrate cancer, growth restriction

Question 2

Bisphosphonates: Alendronate

Answer 2

Inhibit bone resorption by attaching to bony surfaces undergoing active resorption, inhibits osteoclast recruitment onto bone surface, inhibits action of osteoclasts, induces apoptosis of osteoclasts, Inhibits farnesyl diphosphate synthase. Thus leads to increase in bone mineral density & reduced fracture risk
For prevention & tto of osteoporosis in postmenopausal women, increases bone mass in men w osteoporosis, glucocorticoid induced osteoporosis, Paget’s disease
Adverse Effects: hypocalcemia, hypophosphatemia, acid reflux, ab pain, MSK pain, cramps, esophageal ulcer, osteonecrosis of jaw

Question 3

Calcitonin

Answer 3

Synthesized by C cells of thyroid, secretion stimulated by increased plasma Ca+
Binds to osteoclasts & inhibits bone resorption, promotes renal excretion of Ca+ & phosphate by decreasing tubular reabsorption
For osteoporosis, increase spinal bone mass, may reduce risk of vertebral fracture
Adverse Effects: If nasal spray then rhinitis, epistaxis, sinusitis, back pain, arthralgia & headache. If injection then nausea, flushing, headache

Question 4

Denosumab

Answer 4

RANKL inhibitor, suppresses bone resorption & bone formation. Thus reduces risk of vertebral & non vertebral fractures
For postmenopausal osteoporosis
Adverse Effects: increase risk of osteonecrosis of jaw following oral or dental procedures

Question 5

PTH: Teriparatide (PTH 1-34)

Answer 5

Accelerates removal of Ca+ from bone to increase Ca+ levels in blood, stimulates osteoblast function, increases GI absorption of Ca+, increases renal reabsorption of Ca+. Decreases risk of vertebral & non vertebral fractures
For osteoporosis in postmenopausal women w high risk of fracture, previous osteoporotic fracture, very low BMD, primary or hypogonadal osteoporosis in men w high risk of fractures
Adverse Effects: leg cramps, arthralgia, transient hypercalcemia (S&S nausea, vomiting, constipation, low energy, muscle weakness), rash, dizziness, headache
Black box warning: osteosarcoma risk in animals
Don’t use in Paget’s disease of bone, radiation therapy, bone metastasis, hypercalcemia, Pregnant & Nursing

Question 6

Raloxifene

Answer 6

Selective Estrogen Receptor Modulator (SERM)
Acts as an estrogen agonist on bone, antagonist on breast & endometrium
For prevention & tto of osteoporosis in postmenopausal women
Adverse Effects: hot flashes, DVT, leg cramps

Question 7

Estrogen Hormone replacement therapy (EHRT)

Answer 7

Anti-resorptive
For prevention of osteoporosis, menopause symptoms, vulvar & vaginal atrophy associated w menopause
Adverse Effects: breast cancer, CAD, stroke, venous thrombosis

Question 8

Strontium Ranelate

Answer 8

Increases bone formation & inhibits bone resorption. Thus promotes bone formation
For tto of osteoporosis
Not approved in the US