Exam5- Osteoporosis Flashcards
(24 cards)
RANKL
on osteoblasts and activates osteoclasts
Osteoprotegerin
binds to RANKL
prevents interaction of osteoclasts and blasts
-this is how estrogen limits bone resorption
Vitamin D
(+) Ca2+ absorption
(+) bone resorption and then eventually bone growth
Parathyroid hormone
(+) conversion of vit. D to calcitrol
(+) osteoblasts AND osteoclasts to bone remodel
(+) renal resorption of Ca2+
calcitonin
(-) intestinal absorption and renal reabsorption of Ca2+
(-) osteoclasts
(-) reduces circulating calcium
calcitrol effects
=potent vitamin D (D3)
(+) Ca2+ release from bone
(-) Ca2+ elimination from kidney
(+) Ca2+ absorption in Gi
NET EFFECT IS BUILDING BONE
vitamin d deficiency =
hypocalcemia/demineralization of bone
kids=rickets
adults=osteomalacia
vitamin D deficiency treatmetn
suplements
vitamin D2 (ergocalciferol)
Vitamin D3 (cholecalciferol)
-take with Ca2+ supplements
PTH effects on bone depend on___
concentration and pattern
- low concentration/intermittent = greater effects on osteblasts =BONE GROWTH
- high concentration/constant = greater effects on osteoclasts =BONE RESORPTION
teriparatide
recombinant PTH1-34 used for treatment of osteoporosis
glucocorticoids
(-) bone mineralization
(-) vitamin D effects
PROMOTE OSTEOPOROSIS
-DONT TAKE FOR MORE THAN 2 WEEKS
___ causes osteoporosis
estrogen, calcium of vitamin D deficiency and chronic glucocorticoid therapy
treatment of osteoporosis
-diet
-active livestyle
-bone density tests
supplements
-calcium, vitamin D
medications
-anti-resorptive meds
-anabolic drugs
anti-resoprtive medication lists
Hormone Replacement Therapy SERMs Salmon calcitonin bisphosphonates denosumab
anabolic drugs lists
teriparitide
estrogen and progestin HRT drugs
permarin- estrogens only (only in women without uteruses)
prempro- estrogens and progestin
=increas OPG
-not first line choice in post menopausal women due to risk of stroke, heart disease, and breast cancer
SERMs
Selective Estrogen Receptor Modulators
=raloxifene
=antagonist at estrogen receptor (reduces breast cancer risk)
=antagonist at estrogen receptor in uterus (no risk for reproductive cancer when administered without progestin)
=partial agonist at estrogen receptors that regulate resorption (protect against osteoporosis)
=risk for blood clots and strokes similar to HRT
-NOT FIRST LINE DRUGS FOR MANAGING OSTEOPOROSIS
Salmon calcitonin
-nasal spray
-peptide secreted by parafollicular cells of the thyroid
-salmon has longer half-life
-inhibits osteoclasts and therefore (-) bone resorption
SECOND CHOICE DRUG because they’re less effective long term than estrogens and bisphosphonates
side effects of salmon calcitonin
five year risk for cancer increased…
bisphosphonates
(-) bone resorption by osteoclasts
FIRST CHOICE DRUGS FOR PREVENTION AND TREATMENT OF OSTEOPOROSIS
-reduces bone density and reduces fractures over 5 years
bisphosphonates adverse effects
bisphosphonate-associated osteonecrosis =avascular necrosis -exclusively in jaw -disrupt the capillary network -60% of cases preceded by tooth extractions
bisphosphonates drug lists
alendronate
risedronate
ibandronate
zoledronic acid
denosumab
-monoclonal antibodies that targets the RANKL
-equal efficacy with bisphosphonates and teriparatide
side effects= increased risk for infection and skin reaction
-indicated when other medications are not effective or tolerated or cases of very high risk of fracture
teriparatide
=recombinant form of PTH1-34 -sc administration -selectively produces PTH effects on bone growth -increases bone density used in cases: 1. bone has been fractured/low density 2. bone density is lost when receiving other antiresorptive treatment -hypothetical risk for osteosarcomas
