Mod 1 lecture 2: calcium homeostasis Flashcards
what is the presentation of hypercalcemia
stones, moans, bones and psychiatric overtones
ECG = shortened QT, ST depression, AV block
what are the common causes of hypercalcemia
hyperparathyroidism, malignancy, granulomatous disease, thiazide, lithium, pancreatitis
what are the interventions for hypercalcemia
IV hydration, calcitonin, bisophosphonates, loop diuretics, glucocorticoids, denosumab, dialysis
what build bone by secreting collagen and catalyzing mineralization
osteoblasts
what dissolve bone by secreting acid and collagenases
osteoclasts
what at low intermittent levels, have an anabolic effect on osteoblasts (build bone)
parathyroid hormone (PTH)
what inhibits apoptosis in osteoblasts and induces apoptosis in osteoblasts
estrogen
what does estrogen deficiency lead to
excess cycles of remodeling and bone resorption resulting in osteoporosis
what stimulates calcium deposition in bones, decrease calcium uptake in kidneys
calcitionin
what increases intestinal and renal uptake of Calcium and phosphate and stimulates calcium release from bones - promotes bone mineralization
vitamin D
what are regulators of bone mineral and calcium homeostasis
osteoblasts
osteoclasts
PTH
estrogen
calcitonin
vitamin D
what is the MAO for bisphosphonates
inhibits osteoclast activity, reducing bone resorption and turnover
what are the indications for alendronate
osteoporosis, paget disease of bone, osteopenia (in non-ambulatory patients)
what are the indications for risedronate
osteoporosis, paget disease of bone
what are the indications for ibandronate
osteoporosis
what are the indications for zoledronic acid
osteoporosis, malignant hypercalcemia, bone metastasis, multiple myeloma
what are the bisphosphonates
aldendronate
risedronate
ibrandronate
zoledronic acid
what are the side effects of bisphosphonates
bone, joint and muscle pain
N, abd pain, heartburn, diarrhea, constipation
irritation to upper GI mucosa (risedronate < alendronate)
HA
atypical femur fractures, osteonecrosis of the jaw
flu-like symptoms with IV bisphosphonates
hypocalemia - Ca and Vit. D supplementation recommended
what are the contraindications for bisphosophonates
esophageal disorders (achalasia, esophageal strictures, osophageal varices, Barrett’s esophagus)
renal insufficiency (CrCl < 35)
hypocalcemia
food interferes with absorption - take with water on empty stomach and wait 30-60 minutes before eating
what is the MOA of Calcitonin
antagonizes the effect of PTH, inhibits osteoclast activity and promotes renal excretion of Ca2+
what are the indications of calcitonin
hypercalcemia, paget disease of bone, postmenopausal osteoporosis, pain from osteoporotic fracture
what are the AE of calcitonin
rhinitis, epistaxis, back pain, N/V, bronchospasms, hypocalcemia, anaphylaxis (rare)
what is the MOA for vitamin D
cholecalciferol (vit D3) is a provitamin. active metabolite 1,25-dihydroxyvitamin D stimulates calcium absorption from small intestine and promotes bone mineralization
what are the indicatiosn for vitamin D
vitamin D deficiency, osteopososis, hypoparathyroidism
what are the contraindications of vitamin D
hypercalcemia, primary hyperparathyroidism, sarcoidosis
what is the MOA for Calcitrol
vitamin D analog - stimulates calcium and phosphorus absorption, decrease PTH synthesis, stimulates bone mineralization
what are the indications for calcitriol
renal failure, hypoparathyroidism, rickets, hypophosphatemia
what are the AE of calcitriol
hypercalcemia, hyperphoephatemia, N/V
what are the contraindications of Calcitriol
pancreatitis, soft tissue calcification, arrhythmias
What is the MOA for denosumab
recombinant antibody that inhibits RANK-ligand to bind to RANK (antiresorptive)
what are the indications for denosumab
osteoporosis, cannot tolerate or unresponsive to bisphosphonates, renal impairment
what are the SE of denosumab
osteonecrosis of the jaw, atypical subtrochanteric fracture, bone pain
what are the contraindications of denosumab
hypocalcemia
What is the MOA of teriparatide (forteo)
recombinant PTH
anabolic effect on bone metabolism by stimulating bone formation and activating bone remodeling
treatment duration < 2 years in lifetime
what are the indications for teriparatide
osteoporosis (but not used often)
what are the AE of teriparatide
generally well tolerated. hypercalcemia and hypercalciuria. orthostatic hypotension
US boxed warning: risk of Osteosarcoma
what are the contraindications of teriparatide
hypercalcemia, severe renal impairment
What is the MOA for Raloxifene
selective estrogen receptor modifier (SERM)
acts like estrogen agonist in bone thereby decreasing bone resorption and overall bone turnover
bone density is increased
what are the indications for Raloxifene
osteoporosis in postmenopausal women
what are the AE of Raloxifene
hot flashes, leg cramps, peripheral edema, DVT/PE
what are the contraindications of Raloxifene
history of DVT/PE, pregnancy
what are the effects of thiazides (HCTZ) on calcium levels
decrease urinary Ca2+ excretion
inhibits secretion of Calcium sometimes leading to elevated calcium levels in the blood
what are the effects of loops diuretics (furosemide) on calcium levels
increase urinary calcium concentration
useful in treatment of hypercalcemia because it stimulates tubular calcium excretion
what are the toxicity symtpoms of fluoride
GI effects such as N/V/D, severe cases renal or cardiac dysfunction
where is the total body fluoride contained
in bones and teeth
