PARATHYROID HORMONE, CALCIUM, AND VITAMIN D

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PARATHYROID HORMONE, CALCIUM, AND VITAMIN D

• Citation Dr. Walters note packet

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• From where is PTH released, and what causes its
  release?
• Parathyroid gland, decr in serum Ca
• What are 3 effects of PTH?
• 1. stimulates osteoblasts to release osteoclast
  differentiation factor ? increase osteoclasts
• 2. incr renal reabsorption of Ca
• 3. incr hydroxylase activity (converts
  calcifidiol ? calcifitriol)
• A. Incr Ca absorption by intestine
• B. Incr bone resorption
• C. Decr renal excretion of Ca
• What are these effects mediated by?
• cAMP and IP3/DAG

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• What Rx is recombinant human PTH?
• Teriparatide
• What are the uses of this Rx?
• A. Tx osteoperosis in postmenopausal women
• B. Ddx pseudo vs true hypoparathyroidism
• What are the cAMP levels in pseudo?
• Normal, b/c target organ resistant
• What are the cAMP levels in true?
• Incr, b/c nothing wrong w/ target tissue,
  therefore if give Rx ? normal response (which is
  an incr in cAMP)
• What are the side effects of this Rx?
• Hypercalcemia, hyperuricemia

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• From where is Calcitonin released, and what
  causes its release?
• Thyroid gland, incr Ca
• What Rx requires skin test?
• Calcitonin Salmon
• What are the side effects of Calcitonin Salmon?
• Flu-like sx (m. aches, sinusitis, N, V),
  hypersensitivity rxn
• Is a skin test needed for Calcitonin Human?
• no

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• What class of Rxs are pyrophosphate analogs?
• Biphosphonates
• What is the mech?
• Stabilize hydroxyapatite prevent
  demineralization
• What Rx also inhibits mineralization?
• Etidronate
• What 2 Rxs are used for hypercalcemia of
  malignancy?
• Pamidronate, Zolendronate
• What are the other 3 biphosphonates?
• Alendronate, Tiludronate, Risedronate
• What is the absorption in the GI tract?
• Poor, take on empty stomach, N and diarrhea common

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• Calcium Salts
• What Rx is an acidifying salt?
• Ca Chloride
• What Rx has the highest Ca?
• Ca Carbonate, 40, used in antacids
• What Rx is used to control hyperphosphatemia in
  end stage renal dz?
• Ca Acetate
• What 2 Rxs are not used to control
  hyperphosphatemia in end stage renal dz?
• Tricalcium phosphate b/c dont need more
  phosphate, would exacerbate problem
• Calcium carbonate b/c highest Ca, easy to OD

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• What Rx is considered (by some) to be the best tx
  for hypocalcemic tetany?
• Ca Gluconate
• What are the other 2 Ca salts?
• Ca citrate, Ca lactate
• What are the side effects for all Ca salts?
• Anorexia, N, V, constipation, confusion,
  delirium, stupor, COMA
• What Rxs interact w/ Ca salts?
• Thiazides
• Tetracyclines
• Ca channel blockers
• Iron salts

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• Vitamin D
• What does Calcitriol (the active form) do?
• 1. incr intestinal Ca absorption
• 2. incr bone resorption
• 3. decr Ca excretion by kidneys
• What is the mech for incr Ca absorption?
• 1. Binds Hormone Response Element ? incr
  transcription of Ca binding protein (Calbindin)
  this protein transports Ca fr the mucosal
  side to serosal side of intestinal lumen
  transcription is slow
• 2. Transcaltechia occurs w/in minutes
  endocytotic uptake of Ca by mucosal cell brush
  border
• What is the mech for incr bone resorption?
• Stimulates osteoblasts to release
• 1. IL-1 (promotes resorption)
• 2. substances that incr proliferation of
  osteoclasts

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• What Rx is 25-OH-D3 and must be activated by the
  kidney?
• Calcifediol
• What Rx is vitamin D2?
• Ergocalciferol (Calciferol)
• What Rx is 1,25 dihydoxy-D3 and active form is
  made in the kidney?
• Calcitriol
• What Rx is a synthetic isomer of Vit D2 and must
  be hydroxylated by the liver to its active form
  (kidney not involved)?
• Dihydrotachysterol
• What Rx has its non-hydroxylated form made in the
  skin?
• Cholecalciferol
• What are the above Rxs used for?
• Dietary supplements or to tx hypocalcemic tetany,
  osteomalacia, osteoporosis, hypoparathyroidism,
  rickets

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• What Rx is for hyperparathyroidism in pts
  undergoing chronic renal dialysis?
• Doxercalciferol
• What Rx is synthetic D3 for psoriasis and
  inhibits growth development of keratinocytes?
• Calcipotriene
• What Rx is synthetic D3 for hyperparathyroidism
  from chronic renal failure?
• Paricalcitol
• What are the side effects for all vit D rxs?
• Hypervitaminosis D, arrested growth (may not be
  reversible)
• What are the Rx interactions?
• Digoxin, verapamil
• What Rxs are associated with Rickets and
  Osteomalacia due to decr intestinal absorption of
  calcium?
• Phenytoin, phenobarbital

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• Na Fluoride
• What is the use?
• Dental caries, best if given before eruption of
  permanent teeth
• What is the mech?
• Anion exchange Fl- deposits in tooth enamel in
  exchange for hydroxyl or citrate anions.