ic14 osteoporosis pharmacology Flashcards
moa of biphosphonates
slow bone loss by increasing osteoclast cell death
sources of calcium
PTH is released when low plasma calcium levels are detected
1) dietary = PTH increases vit D synthesis in kidney = increase calcium absorption from intestines
2) kidney = affected by parathyroid hormone = increase calcium reabsorption in the urine
3) bone = increase calcium release from bones (activate osteoclasts) via PTH + vit D
vit D source
skin and UVB
convert 7 dehydrocholesterol = vit d3 (cholecalciferol) = stored in liver
= activated by kidney to 25(oh)vitD
PTH stimulates activation of vit D3 to 1,25 dihydroxyvitD by increasing 1-alpha hydroxylase
what is denosumab
human monoclonal antibody against RANKL, required for binding with RANK receptors on osteoclasts for its formation, differentiation, activation, survival
some adr of denosumab
MSK: muscle, back, bone or joint pain
GI: n/v, constipation or diarrhoea
slight tiredness
increased cholesterol levels
why do not discontinue denuosumab?
increased risk of spinal column fractures when discontinued
pregnancy status for denosumab
X for pregnancy
place in thrapy for oestrogen in osteoporosis?
can help to maintain bone density
BUT
increased risk of breast cancer ,blood clots, stroke.
used for
(i) bone health in younger women
(ii) women with other menopausal sx requiring tx
what is raloxifene
selective oestrogen receptor modulator
- mixed oestrogen receptor agonism and antagonism
- mimc effets of oestrogen on bone density in postmenopausal women
lowers risk of some breast cancers but still increases risk to blood clots
- also causes hot flashes
role of calcitonin (moa and indication)
reduces BLOOD calcium and opposes effects of PTH
= inhibit osteoclast activity in bones
HOWEVER, not frequently used
naturally released by thyroid glands to regulate ca2+ lv in blood by decreasing it.
UPTODATE: Osteoporosis, postmenopausal (intranasal or injection): Treatment of osteoporosis in patients >5 years postmenopause.
adr of calcitonin
red streaks on skin; redness of face, neck, arms, and occasionally upper chest
feeling of warmth
injection site reaction
contraindications of calcitonin
hypersx and hypocalcaemia
MOA of romosozumab (and what it is)
humanised mouse monoclonal antibody against sclerostin
removes sclerostin inhibition of canonical Wnt signalling pathway that regulates bone growth in osteoblasts (allows for differentiation of pre osteoblast to osteoblast) = increase bone formation and decrease bone resorption.
indication of romosozumab
women at high risk of fracture
OR
who have failed or are intolerant to other osteoporosis therapies
directions for use of romosozumab
once monthly for 12 months (SC injection)