Chapter 42 - Calcium and Bone Metabolism

Question 1

Calcium Preparations

• Calcium

Answer 1

 Calcium
 MOA: Increases levels of calcium in the body; absorbed in small intestine, assisted with absorption by vitamin D
 Use: Insufficient calcium in body, osteoporosis, calcium channel blocker overdose
 AE: Hypercalcemia, systemic effects, GI effects (N/V, constipation, abdominal pain, anorexia), CNS effects (apathy, poor memory, disorientation, depression, drowsiness), cardiac effects (dysrhythmias, prolonged QT interval and inverted T wave), weakness, decreased skeletal/smooth muscle tone, dysphagia, polyuria, polyphagia
 Contra: Cancer metastasized in bone, atrial fibrillation (can prolong QT interval), people who have renal calculi (can increase)
•Monitor serum levels (normal range 8.5-10.5 mg/dL), monitor for decreasing signs of tetany

Question 2

Vitamin D

• Vitamin D

Answer 2

 Vitamin D
 MOA: Increases calcium and phosphorus absorption from the GI tract. Promotes movement of calcium from bones and kidneys to raise calcium levels
 Use: Chronic hypocalcemia, decreased parathyroid hormone, osteoporosis, vitamin D deficiency
 AE: Hypervitaminosis D, hypercalcemia; can lead to kidney stones, irreversible kidney damage, muscle and bone weakness, tetany
• Someone who does not have good kidney function often has a difficult time maintaining calcium and vitamin D levels due to renal impairment
• MONITOR CLOSELY (increased risk of fractures, etc) because they are at higher risk of having these hormones lower in blood

Question 3

Biphosophonates

• alendronate (Fosamax)

Answer 3

 alendronate (Fosamax)
 MOA: Suppresses osteoclast activity on newly formed resorption surfaces (resorption = breakdown). Suppress further activity in areas that have been broken down, which reduces bone turnover
 Use: Prevent and treat osteoporosis in postmenopausal women (and in men). Pagett’s disease and glucocorticoid induced osteoporosis
AE: Not used in children. Esophagitis, dysphagia, H/A, muscle pain, decreased serum calcium levels can occur
 Admin: Need to take w/ full glass of water at least 30 minutes before breakfast or any other drug. Must maintain upright in a chair or standing for at least 30 minutes after administration. These measures are to promote absorption into system and reduce AEs