Conditions Affecting the Musculoskeletal System and PharmacotherapyPart Three: Metabolic DX – Osteoporosis and Fractures Flashcards
Exam 4 (Final)
Normal A&P: Calcium
What are the roles of calcium?
Blood coagulation
Integrity
Normal A&P: Calcium
Roles of Calcium: Integrity of what?
Bones, nerves, muscle, heart
Bones remodel continuously
Normal A&P: Calcium
Roles of Calcium: Integrity
Bones remodel continuously what is involved?
osteoclasts resorb (breakdown) old bone
osteoblasts lay down new bone
Osteoclasts
Resorb (breakdown) old bone
Osteoblasts
lay down new bone
Normal A&P: Calcium
Where is the majority of calcium stored?
Majority stored in bone ~ 98%
Normal A&P: Calcium
Factors affecting regulation of calcium include:
PTH
Vitamin D
Calcitonin
Normal A&P: Calcium
When not stored in the bones, where is calcium located?
Remainder present in blood
Normal A&P: Calcium
What are normal levels?
Normal (Total): 8.9 to 10mg/dL
Normal A&P: Calcium
When in the blood, what is calcium binded to?
50% bound to albumin, citrate, & phosphate
Normal A&P: Calcium
When in the blood, calcium is binded to proteins, when not attached to protein how is it?
50% free, active, ionized, clinically important & participates in bodily processes
Normal A&P: Calcium
Calcium absorption: Where is calcium absorbed?
Small intestines ~ ingested calcium
Normal A&P: Calcium
Calcium absorption: What is calcium absorption increased by?
Increased by PTH & vitamin D
Normal A&P: Calcium
Calcium absorption: What is it reduced with?
Meds:
Oxalic acid
Phytic acid & insoluble fiber
Normal A&P: Calcium
Calcium absorption: What meds reduce calcium absorption?
GCs, Cinacalcet, some chemo, TCNs, Levothyroxine, Phenytoin, Phenobarb, Loops
Normal A&P: Calcium
Calcium absorption: What are examples of oxalic acid that reduce calcium absorption?
Oxalic acid ~ spinach, rhubarb, swiss chard, beets
Normal A&P: Calcium
Calcium absorption: What examples of Phytic acid & insoluble fiber
that reduce calcium absorption?
bran, grain cereals
Normal A&P: Calcium
Calcium excretion: Where is it primarily excreted?
Primarily through kidney
Normal A&P: Calcium
Calcium excretion: Calcium primarily excreted through the kidney is determined by what?
Loss determined by GFR & tubular reabsorption
Normal A&P: Calcium
Calcium excretion: Calcium primarily excreted through the kidney-what is excretion reduced by?
Excretion reduced by PTH & vitamin D, & thiazides
Normal A&P: Calcium
Calcium excretion: Calcium primarily excreted through the kidney-what is excretion increased by?
Increased excretion ~ loops, calcitonin
Normal A&P: Calcium
What happens when there is Low Serum Calcium?
PTH (pulls) secretion
Normal A&P: Calcium
When there is Low Serum Calcium, PTH pulls secretion, what does this promote?
Ca resorption from bone
Tubular reabsorption of Ca from kidney
Activation of vitamin D promotes increased absorption of calcium from the intestine
Pulls from bones –> demineralized
Normal A&P: Calcium
What does Vitamin D do?
Increases calcium resorption from bone
Decreases calcium excretion by the kidney
Increases calcium absorption from the intestine
Normal A&P: Calcium
What does Vitamin D work similar to?
Works similar to PTH
Normal A&P: Calcium
What does a high serum calcium do?
Ca leaves blood, causing a Suppression of PTH release
and no vitamin D activation
Normal A&P: Calcium
What happens when calcitonin (keeps) is released by thyroid?
decrease plasma Ca levels
Inhibits calcium resorption in bone
increase in renal excretion
No effect on calcium absorption
Slide 5
Normal A&P: Vitamin D3
Pharmokinetics: Where is Vitamin D3 absorbed from?
Absorbed from small intestine
Normal A&P: Vitamin D3
Pharmokinetics: What is needed for Vitamin D3 to be absorbed?
Need bile for absorption
Normal A&P: Vitamin D3
Pharmokinetics: Where is Vitamin D3 stored?
Stored in liver
Normal A&P: Vitamin D3
Pharmokinetics: Where is Vitamin D3 excreted?
Excreted in bile
Normal A&P: Vitamin D3
Pharmokinetics: What converts Vitamin D3 to its active form?
Kidney converts it to active form
Normal A&P: Vitamin D3
Pharmokinetics: How is Vitamin D3 excreted in urine?
Urinary excretion minimal
Vitamin D:
What are the forms of Vitamin D?
Ergocalciferol (vitamin D2)
Cholecalciferol (vitamin D3)
Vitamin D:
What form of Vitamin D occurs in plants?
Ergocalciferol (vitamin D2)
Vitamin D:
What is Ergocalciferol (vitamin D2) used for? In what form are they?
Used for hypoparathyroidism,
Vit D-resistant rickets,
hypophosphatemia
Capsules & solution
Vitamin D:
How is Cholecalciferol (vitamin D3)
produced?
Produced naturally from sunlight
Vitamin D:
What food has Cholecalciferol (vitamin D3)? How else is D3 available?
Animal-sourced foods (oily fish, egg yolk, butter)
Available pharmaceutically (multiple doses)
Vitamin D:
What are therapeutic uses of Cholecalciferol (vitamin D3)? How is it available?
Therapeutic uses
Deficiency – px & tx
Bone health
Calcium absorption
Capsules, liquid, tablets
Vitamin D: What are Physiologic actions similar to?
Similar to PTH
Vitamin D: What are Physiologic actions of Vitamin D?
Increases Ca & Phos
Vitamin D:
Physiologic actions of Vitamin D: How does Vitamin D increase Ca and Phos?
↑ intestinal Ca absorption
↑ resorption Ca in bone
↓ renal Ca excretion
Vitamin D toxicity:
What are early symptoms?
Early symptoms: Weakness, fatigue, nausea, vomiting, anorexia, abdominal cramping, constipation