Bone Disorders

Question 1

Treatment of nutritinal osteomalacia & rickets is……, treatment of renal rickets is……

Answer 1

Ca+vit D (IM in malapsorption)
Ca+calcitriol or alfacalcidiol

Question 2

List drugs causing osteoporosis

Answer 2

Heparin, aluminum antacids, phenytoin, PPI, glucocorticoids

Question 3

1st line treatment of osteoporosis is……

Answer 3

Bisphosphonates OR denosumab

Question 4

Describe mechanism of action of bisphosphonates

Answer 4

Inc osteoclastoc apoptosis & inhibit cholesterol pathway important for osteoclastic function. This result in a small inc in bone mass & dec risk of fractures. Beneficial effects of alendronate persist over several yrs of therapy (but discontinuatio results in a gradual loss of effects).

Question 5

List indications of bisphosphonates

Answer 5

1. Hypercalcemia associated with malignancy
2. Osteoporosis (inc bone mineral density)
3. Paget’s disease of bone, dec bone turnover

Question 6

List adverse reactions of bisphosphonates

Answer 6

1. Gastric & esophageal irritation (take with a full glass of water while sitting upright for 30 min) CI: peptic ulcer & esophageal motility disorders
2. Osteonecrosis of jaw
3. Given cautiously in renal impairment

Question 7

Mechanism of action & use of denosumab

Answer 7

Mab against RANKL inhibit osteoclast formation & function —> inhibit bone resorption
Used in postmenoposal osteoporosis in women at high risk of fracture & those intolerant or unresponsive to other osteoporosis therapies.
SC injection every 6 mons

Question 8

List adverse effects of denosumab

Answer 8

1. Inc risk of infections
2. Dermatological reactions
3. Hypocalcemia, osteonecrosis of jaw & atypical features.

Question 9

Mechanism, uses & AEs of calcitonin

Answer 9

M, reduces bone resorption but less effective than bisphosphonates & relief of pain associated with osteoporotic fracture.
U, Paget’s disease & hypercalcemia
AE,
1. N&V& bad tase
2. Facial flushing, swelling of hands
3. Runny nose, nasal bleeding & nasal irritation (with nasal spray)

Question 10

……is calcitonin preparation with high t1/2 & potency

Answer 10

Salmon calcitonin

Question 11

Mechanism of action & indications of estrogen

Answer 11

-inhibit bone resorption induced by parathyroid hormone
-Used in Prevention & treatment of osteoporosis in post-menopausal women (may inc risk of cancer)

Question 12

Mechanism of action & adverse effects of raloxifene

Answer 12

Selective estrogen receptor modulator (partial agonist) with effects similar to estrogen on bone (inhibit bone resorption) but not on brest or uterus (no risk of cancer)
AEs: hot flashes, sweating, leg cramps, thrombophlebitis & thromboembolism.(CI: venous thrombo-embolism)

Question 13

Mechanism of action & indications of SERM

Answer 13

Bazedoxifene: SERM, estrogen-like effects on bone (inc bone density) and lipids (dec LDL); antiestrogenic in uterus & breast (reduces risk of endometrial hyperplasia which can occur with conjugated estrogens)
Used in osteoporosis & menopausal vasomotor symptoms.

Question 14

Mechanism of action of romosozumab

Answer 14

Sclerostin inhibitor

Question 15

Mechanism of action & indications of teriparatide

Answer 15

Promote bone formation by stimulating osteoblastic activity
Reserved for patients with high risk of fractures who have failed or cannot tolerate other therapies.

Question 16

Mechanism of action & indications & side effects of stronium

Answer 16

M, inc bone formation, calcimimetic, stimulates Ca++ receptors causing pre-osteoblasts to differentiate into osteoblasts. Inhibit bone resorption (osteoclasts)
U, severe osteoporosis, prevents fractures in older women
SEs, may induce MI & allergic reactions

Question 17

Indications of vitamin D

Answer 17

1. Prevention & cure of rickets in children & osteomalacia in adults
2. Osteoporosis
3. Hypoparathyroidism

Question 18

……don’t require renal activation

Answer 18

Alfacalcidiol & calcitriol