Chapter 44 Drug Therapy to Regulate Calcium and Bone Metabolism PDF

Chapter 44 Drug Therapy to Regulate Calcium and Bone Metabolism  Three hormones Calcium and Bone oParathyroid hormone (PTH) Metabolism oCalcitonin; vitamin D Regulation #1 Decreased serum calcium levels (hypocalce...

Chapter 44 Drug Therapy to Regulate Calcium and Bone Metabolism  Three hormones Calcium and Bone oParathyroid hormone (PTH) Metabolism oCalcitonin; vitamin D Regulation #1 Decreased serum calcium levels (hypocalcemia) oHormonal levels activate to raise them. oTetany Elevated serum calcium levels (hypercalcemia) oHormonal levels respond to lower them. Copyright © 2025 Wolters Kluwer. All rights reserved. 2  Is the following statement True or False? Question #1 There are two hormones that regulate calcium and bone metabolism. Copyright © 2025 Wolters Kluwer. All rights reserved. 3  False Answer to Question #1 Rationale: There are three hormones that regulate calcium and bone metabolism: parathyroid hormone (PTH), calcitonin, and vitamin D, which maintain normal serum levels of calcium in homeostasis. Copyright © 2025 Wolters Kluwer. All rights reserved. 4  Hormone action alters Calcium and Bone oAbsorption of dietary calcium from GI tract Metabolism Regulation #2 oMovement of calcium from bone to serum oExcretion of calcium through the kidneys Copyright © 2025 Wolters Kluwer. All rights reserved. 5  Parathyroid hormone (PTH) Calcium Metabolic oStimulated by low serum calcium levels Hormones #1 oActs on bones, intestines, and kidneys to increase serum calcium levels Bones:  breakdown Intestines:  calcium absorption from food Kidneys: less urinary calcium excretion Copyright © 2025 Wolters Kluwer. All rights reserved. 6  Calcitonin Calcium Metabolic oSecretion controlled by ionized serum Hormones #2 calcium flowing through the thyroid gland  serum ionized calcium,  calcitonin secretion oFunction to lower serum calcium in the presence of hypercalcemia oRapid action, short duration Copyright © 2025 Wolters Kluwer. All rights reserved. 7  Vitamin D (calciferol) Calcium Metabolic oFat-soluble vitamin Hormones #3 oRaises serum calcium levels  intestinal absorption of calcium Mobilizing calcium from bone oPromotes bone formation oConverts to action in liver and kidneys Copyright © 2025 Wolters Kluwer. All rights reserved. 8  Is the following statement True or False? Question #2 The main action of calcitonin is to raise serum calcium levels by increasing intestinal absorption of calcium and mobilizing calcium from bones. Copyright © 2025 Wolters Kluwer. All rights reserved. 9  False Answer to Question #2 Rationale: The main action of calciferol (vitamin D) is to lower serum calcium levels by increasing intestinal absorption of calcium and mobilizing calcium from bones. Copyright © 2025 Wolters Kluwer. All rights reserved. 10  Hypocalcemia; hypercalcemia Calcium Disorders oCan be life threatening oCharacterized by Increased resorption of calcium Loss of bone mass oWeaken bones Lead to fractures, pain, disability Copyright © 2025 Wolters Kluwer. All rights reserved. 11  Dietary measures to ensure adequate calcium Osteoporosis intake Prevention Use of medications to prevent osteoporosis Adequate dietary intake of vitamin D Lifestyle changes oRegular exercise oSmoking cessation Medications that can contribute to osteoporosis oChronic corticosteroid therapy oPhenytoin and phenobarbital Copyright © 2025 Wolters Kluwer. All rights reserved. 12  Goal of therapy Principles of Drug oRestore normal calcium balance in body Therapy oHypocalcemic drugs Help to correct deficit; reduce risk of tetany; slow osteoporosis oHypercalcemic drugs Support treatment of underlying condition; control serum calcium levels Copyright © 2025 Wolters Kluwer. All rights reserved. 13  Hypocalcemia treatment; osteoporosis Drug Therapy #1 prevention and treatment oCalcium and vitamin D supplements Hypercalcemia treatment oBisphosphonates, calcitonin, corticosteroids, 0.9% sodium chloride intravenous (IV) infusion Osteoporosis treatment oBisphosphonates, calcitonin, estrogens, and antiestrogens Copyright © 2025 Wolters Kluwer. All rights reserved. 14  Calcium carbonate or calcium citrate Drug Therapy #2 oIV calcium is essential for the treatment of acute, severe hypocalcemia. Vitamin D oRecommended dietary allowance:15 mcg/day for 1 to 70 years of age; 20 mcg/day for adults 71 years and older; adequate intake for infants 0 to 12 months is 10 mcg/day Bisphosphonates oInhibit calcium resorption from bone oPrototype: alendronate Calcitonin oTreatment of hypercalcemia, Paget disease, and postmenopausal osteoporosis Copyright © 2025 Wolters Kluwer. All rights reserved. 15  Acute hypercalcemia (severe symptoms or a Emergency serum calcium level greater than 14 mg/dL) Treatment of oA medical emergency Hypercalcemia oRehydration is a priority. Administer an IV saline solution (0.9% sodium chloride) at an initial rate of 200 to 300 mL/hour and then adjust it to maintain a urine output of 100 to 150 mL/hour. Copyright © 2025 Wolters Kluwer. All rights reserved. 16  Children Use in Special Older adults Populations Abnormal kidney function Hepatic impairment Home care Copyright © 2025 Wolters Kluwer. All rights reserved. 17  Preventing interactions Nursing Administering the medication Implications Assessing for therapeutic effects Assessing for adverse effects Patient teaching Copyright © 2025 Wolters Kluwer. All rights reserved. 18