Pharmacologic Calcium Therapy PDF

11/27/23, 4:52 AM Realizeit for Student Pharmacologic Therapy To ensure adequate calcium intake, a calcium supplement with vitamin D may be prescribed and taken with meals or with a beverage high in vitamin C to promote absorption. The recommended daily dose should be split and not taken as a sing...

11/27/23, 4:52 AM Realizeit for Student Pharmacologic Therapy To ensure adequate calcium intake, a calcium supplement with vitamin D may be prescribed and taken with meals or with a beverage high in vitamin C to promote absorption. The recommended daily dose should be split and not taken as a single dose (Drezner, 2019). Common side effects of calcium supplements are abdominal distention and constipation. Calcium from foods is better absorbed, but calcium supplements may be necessary for patients who are lactose intolerant. Meta-analysis findings demonstrate that vitamin D taken alone is not effective in primary prevention of fractures. However, vitamin D plus calcium does reduce the risk of fractures in patients who are found to be vitamin D deficient by laboratory testing (USPSTF, 2018). Calcium and vitamin D should be taken as supplements to drugs prescribed to treat osteoporosis. These types of drugs include bisphosphonates, estrogen agonist/antagonists, and receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors. Salmon egg based PTH is no longer a therapy, but synthetic human PTH analogues are used in patients with advanced osteoporosis or who are treatment resistant (Robinson, 2020). Bisphosphonate therapy is no longer recommended for patients who only have evidence of osteopenia without reaching the precise DEXA scores that define osteoporosis. These medications must be given on an empty stomach, only with water, and the person must sit upright for at least 30 minutes after ingestion. There are many gastric and esophageal risks, including gastritis, ulceration, and GI bleeding. Contradictions include previously known Barrett esophagus, low serum calcium levels, and pregnancy (Robinson, 2020). Atrial fibrillation has been reported after chronic use of these medications. Two rare side effects include osteonecrosis of the jaw (more likely with intravenous [IV] preparations of these medications) and subtrochanteric fractures. Concerns about these rare adverse effects must be addressed to ensure the patient will adhere to the therapeutic plan and take the medication (Robinson, 2020). Calcium Preparations Calcium is available in many different forms. These preparations differ mainly in the amounts of calcium they contain and their routes of administration. It is important to note that even if people have normal serum levels of calcium, their diets may not contain enough calcium; they may need https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 1/10 11/27/23, 4:52 AM Realizeit for Student calcium supplements. Experts believe that the diets of most people of all ages, but especially of young women and older adults, are deficient in calcium. Pharmacokinetics and Action Absorption of calcium occurs in the small intestine, where approximately one third of the amount consumed is actually absorbed. PTH and vitamin D increase the absorption of calcium. Excretion primarily occurs in the feces, with the remainder excreted by the kidneys. PTH decreases renal excretion of calcium. Oral and IV calcium preparations replace lost calcium and help maintain normal calcium levels. Use Oral calcium (e.g., calcium carbonate or calcium citrate) provides supplemental calcium when diet alone is insufficient to meet body requirements. Also, it is useful for treatment of chronic, nonemergent hypocalcemia, regardless of the cause. In addition, it provides relief from symptoms of acid indigestion and heartburn. Finally, it can decrease bone loss and fractures, especially in women. Calcium citrate is reportedly better absorbed than calcium carbonate. IV calcium is essential for the treatment of acute, severe hypocalcemia, which is a medical emergency. It may be necessary to give repeated doses, to give a continuous infusion, or to use oral supplements to avoid symptoms of hypocalcemia and maintain normal serum calcium levels (measured every 4–6 hours). In calcium blocker overdose, calcium gluconate is given by IV infusion to help reverse the vasodilation and decreased myocardial contractility caused by the calcium channel blocker. Use in Older Adults Hypocalcemia is uncommon in older adults because calcium moves from bone to blood to maintain normal serum levels. However, calcium deficiency commonly occurs because of longterm dietary deficiencies of calcium and impaired absorption of calcium from the intestine. As previously stated, osteoporosis is a concern in some women. Although osteoporosis develops in older men, it occurs less often, at a later age, and to a lesser extent than in older women. Both men and women who take corticosteroids are at risk for osteoporosis. The risk is higher with systemic corticosteroids but may also occur with oral or inhaled drugs, especially at higher doses. Use in Patients With Renal Impairment Patients with renal impairment or failure often have disturbances in calcium and bone metabolism. Calcium acetate may be used to prevent or treat hyperphosphatemia. The calcium https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 2/10 11/27/23, 4:52 AM Realizeit for Student reduces blood levels of phosphate by reducing its absorption from foods. It binds with dietary phosphate to produce calcium phosphate, which is insoluble and excreted in feces. Adverse Effects Hypercalcemia produces adverse effects in several body systems. GI effects include anorexia, nausea, vomiting, abdominal pain, and constipation. Central nervous system effects are apathy, poor memory, depression, drowsiness, and disorientation. Cardiac effects include dysrhythmias, and an electrocardiogram (ECG) shows a prolonged QT interval and an inverted T wave. Weakness and decreased tone in skeletal and smooth muscles, dysphagia, polyuria, and polydipsia may also occur. Contraindications Contraindications to calcium preparations include cancer with bone metastases, as well as ventricular fibrillation, hypercalcemia, hypophosphatemia, and renal calculi. Nursing Implications Preventing Interactions Several medications and foods interact with calcium supplements, increasing or decreasing their effects. Also, it is important to note that oral calcium preparations interfere with the absorption of numerous drugs, including atenolol and fluoroquinolones, when the calcium is taken at the same time. In the case of oral tetracyclines, the calcium combines with the antibiotic, preventing its absorption. In addition, calcium preparations and digoxin have similar effects on the myocardium. Therefore, if a patient taking digoxin receives calcium, the risks of digoxin toxicity and cardiac dysrhythmias increase. It is essential to use this combination very cautiously. Use of calcium with phenytoin decreases absorption of both drugs. IV calcium antagonizes the effects of verapamil. Administering the Medication Calcium is available in many different forms; the nurse ensures that the form being given is the correct one. The nurse also makes sure to: Administer oral preparations with or after meals to increase absorption. If used as an antacid, administer after a meal. Administer oral preparations separately from atenolol and fluoroquinolones and more than 2 to 3 hours before or after giving oral tetracycline. Dilute IV preparations in a compatible fluid and administer slowly as a continuous infusion or in divided doses; check pulse and blood pressure closely; monitor the ECG if possible. IV solutions may cause dysrhythmias and hypotension if administered too rapidly. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 3/10 11/27/23, 4:52 AM Realizeit for Student Carefully observe the IV site during administration because IV calcium is irritating to tissues. Do not administer parenteral forms intramuscularly. Assessing for Therapeutic Effects The nurse observes for relief of symptoms of neuromuscular irritability and tetany, such as decreased muscle spasms, decreased paresthesias, absence of Chvostek’s sign, and absence of Trousseau’s sign. He or she also assesses laboratory results for return of serum calcium levels to the normal range of 8.5 to 10.5 mg/dL. Once the hypocalcemia is stabilized, the aim of treatment is management of the underlying cause or prevention of recurrence. If diarrhea or malabsorption is the cause, treatment of the underlying condition decreases loss of calcium from the body and increases absorption. It is also necessary to measure serum magnesium levels; treatment of hypomagnesemia is essential before treatment of hypocalcemia can be effective. Assessing for Adverse Effects The nurse assesses for increased thirst, inability to eat, and increased urination, as well as for constipation and abdominal pain. It is necessary to assess for diminished memory, disorientation, and drowsiness. The nurse checks the ECG for a prolonged QT interval and inverted T wave that results from hypercalcemia. Patient Teaching Box 44.5 presents patient teaching guidelines for calcium preparations. BOX 44.5 Patient Teaching Guidelines for Calcium Preparations Consult with your health care provider before taking calcium supplements. If you need a calcium supplement, your health care provider may recommend calcium carbonate 500 mg twice daily. This calcium supplement contains the most elemental calcium by weight (40%). It is inexpensive and available in a nonprescription form as the antacid Tums, which contains 500 mg of calcium per tablet. Consume good sources of dietary calcium that include milk, yogurt, hard natural cheese, bok choy, broccoli, Chinese/Napa cabbage, collards, kale, okra, turnip greens, fortified breakfast cereals, fortified orange juice, and dried peas and beans. Do not take a calcium supplement with an iron preparation, tetracycline, ciprofloxacin, or phenytoin. Instead, take the drugs at least 2 hours apart to avoid calcium interference with drug absorption. Avoid rhubarb, spinach, bran, and whole-grain cereals in the meal before taking calcium because these foods interfere with calcium absorption. Take oral calcium 1 to 1.5 hours after meals if gastrointestinal upset occurs. Take oral calcium with a full glass of water. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 4/10 11/27/23, 4:52 AM Realizeit for Student Report anorexia, nausea, vomiting, abdominal pain, dry mouth, thirst, or polyuria. Vitamin D Vitamin D is a fat-soluble vitamin used in chronic hypocalcemia if calcium supplements alone cannot maintain serum calcium levels within a normal range. It is also used to prevent deficiency states and treat hypoparathyroidism and osteoporosis. Although authorities agree that dietary intake is better than supplements, some suggest a vitamin D supplement for people who ingest less than the recommended amount. The recommended dietary allowance, or RDA, for vitamin D is 15 mcg/day 1 to 70 years of age and 20 mcg/day for adults 71 years and older to prevent and treat osteoporosis. Adequate intake for infants 0 to 12 months is 10 mcg/day. Pharmacokinetics and Action As a drug, vitamin D is absorbed from the GI tract. It is stored in the liver, skin, and other tissues for months. It is metabolized into its active form in the liver and kidneys. Half of an oral dose is eliminated in the bile. Vitamin D increases calcium and phosphorus absorption from the GI tract. It also promotes movement of calcium and phosphorus from the bones to maintain normal serum calcium levels. In the kidneys, vitamin D decreases elimination of calcium and phosphorus. Use Vitamin D is useful for the treatment of rickets, other vitamin D deficiency diseases, and hypoparathyroidism. It is important to take vitamin D supplements cautiously and not overuse them; excessive amounts can cause serious problems, including hypercalcemia. Vitamin D is also useful if a calcium preparation alone cannot maintain serum calcium levels within a normal range. When vitamin D is given to treat hypocalcemia, frequent measurements of serum calcium levels determine dosage. Usually, people take higher doses initially, and lower doses are appropriate for maintenance therapy. Calcium salts and vitamin D are available over the counter in many combined preparations promoted as dietary supplements. These mixtures are not indicated for maintenance therapy in chronic hypocalcemia. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 5/10 11/27/23, 4:52 AM Realizeit for Student Use in Patients With Renal Impairment Renal disease interferes with metabolism of vitamin D precursors to the active form of vitamin D in the kidneys. If vitamin D therapy is necessary for the treatment of osteomalacia associated with renal impairment, calcitriol (Rocaltrol) is preferable. Calcitriol is the active form of vitamin D and thus undergoes no metabolism. Adverse Effects The principal adverse effects of excessive vitamin D use are hypervitaminosis D and hypercalcemia. This is most likely to occur with chronic ingestion of high doses daily. In children, accidental ingestion may lead to acute toxicity. Of particular significance with vitamin D excess are kidney stones, irreversible kidney damage, and muscle and bone weakness. Box 44.2 discusses symptoms of hypercalcemia, such as tetany. Contraindications Contraindications to vitamin D include hypercalcemia and vitamin D toxicity. It is necessary to withhold all preparations containing vitamin D. Nursing Implications Preventing Interactions Several medications interact with vitamin D, increasing or decreasing its effects. Administering the Medication People may take vitamin D without regard to food. It is important not to take both the vitamin and magnesium-containing antacids or mineral oil. Assessing for Therapeutic Effects The nurse observes for a decrease in symptoms of hypocalcemia and symptoms of rickets or osteomalacia. It is necessary to check that the following laboratory results are normal: serum calcium level, blood urea nitrogen and serum creatinine, and serum phosphate. Improved bone health, as documented by radiograph, should be evident. Assessing for Adverse Effects It is important to monitor serum calcium. If hypercalcemia occurs, the nurse must stop the drug and notify the health care provider. It is necessary to observe for signs and symptoms of vitamin D excess, including headache, somnolence, weakness, irritability, hypertension, cardiac dysrhythmias, kidney stones, polydipsia, polyuria, and bone and muscle pain. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 6/10 11/27/23, 4:52 AM Realizeit for Student Patient Teaching Box 44.7 presents patient teaching guidelines for vitamin D. BOX 44.7 Patient Teaching Guidelines for Vitamin D Take vitamin D supplements only if recommended by your primary health care provider. Avoid unapproved over-the-counter drugs and magnesium-containing antacids. Immediately report early symptoms of vitamin D intoxication: weakness, nausea, vomiting, dry mouth, constipation, muscle or bone pain, and metallic taste. Be aware that certain drugs interact with vitamin D, such as thiazide diuretics, phenytoin, cholestyramine resin, and mineral oil and increase or decrease the effects of the vitamin. Learn about good dietary sources of vitamin D. Food sources of vitamin D include cod liver oil, oysters, mackerel, most fish, egg yolks, fortified milk, some ready-to-eat cereals, and margarine. Understand that a source of vitamin D besides diet is sunlight on the skin. Adequate sun exposure allows the body to produce enough vitamin D to meet daily requirements. Factors that limit vitamin D production through sun exposure include lack of exposure, geographic location, season, use of sunblock, and darker skin pigmentation. Bisphosphonates Bisphosphonates are drugs that bind to bone and inhibit calcium resorption from bone. Although indications vary, the drugs are used mainly in the treatment of hypercalcemia and osteoporosis. Alendronate (Fosamax) is the prototype bisphosphonate. Pharmacokinetics and Action Alendronate is poorly absorbed from the intestinal tract. It is not metabolized. The drug bound to bone is slowly released into the bloodstream. Most of the drug that is not bound to bone is excreted in the urine. Alendronate suppresses osteoclast activity on newly formed resorption surfaces, which reduces bone turnover. This means that bone formation exceeds resorption at remodeling sites, leading to progressive gains in bone mass. Use https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 7/10 11/27/23, 4:52 AM Realizeit for Student Although the main use of alendronate is to prevent and treat osteoporosis in postmenopausal women, it is also used to treat osteoporosis in men. Other uses include the treatment of Paget's disease, an inflammatory bone disease that affects older people, and glucocorticoid-induced osteoporosis in both sexes. The drug is not useful in children. Use in Patients With Renal Impairment Experts do not recommend using alendronate in severe renal impairment (creatinine clearance [CrCl] < 35 mL/min). Adverse Effects Adverse effects of alendronate are usually minor if the doses taken for prevention or treatment of osteoporosis are used and the drug is taken as directed. Patients who do not follow the dosing instructions are at greater risk for esophagitis, dysphagia, and esophageal ulcers/erosions. Other effects include headache, musculoskeletal pain (sometimes severe), and decreased serum calcium. More severe effects may occur with the higher doses taken for Paget’s disease. Rare adverse effects include atypical femur fracture and osteonecrosis of the jaw. Patients on long-term therapy are at greater risk for femur fracture. Greater risk of osteonecrosis of the jaw occurs with higher drug potency, higher cumulative dose, and parenteral route of administration. Experts recommend a drug holiday of 2 to 3 years for women with low risk for fracture after 3 to 5 years of bisphosphonate therapy ( Aggarwal & Masuda, 2018 ). Contraindications Contraindications to alendronate include hypersensitivity to the drug, abnormalities of the esophagus that delay esophageal emptying, and inability to stand or sit upright for at least 30 minutes. People with hypocalcemia require correction of the low serum calcium levels before beginning therapy with alendronate. Caution is warranted with active upper GI conditions. Nursing Implications Preventing Interactions Several medications interact with alendronate, increasing or decreasing its effects. Any food interferes with absorption of alendronate. Administering the Medication The nurse ensures proper administration of alendronate. It is always necessary to take the drug with a full glass of water, not juice or coffee, at least 30 minutes before breakfast and before https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 8/10 11/27/23, 4:52 AM Realizeit for Student taking other drugs. The person must remain upright (either with the head elevated 90 degrees if in bed, sitting upright in a chair, or standing) for at least 30 minutes after administration. These interventions promote absorption and decrease esophageal and gastric irritation. Assessing for Therapeutic and Adverse Effects The nurse observes for improved bone density and absence of fractures. Patients who report thigh pain should have x-rays to check for atypical femur fractures (Brown et al., 2014). Early osteopenia and osteoporosis are asymptomatic. Measurement of bone density is the only way to quantify bone loss. It is also necessary to observe for GI adverse effects, including abdominal distension, acid regurgitation, dysphagia, esophagitis, and flatulence. Patient Teaching Box 44.9 gives patient teaching guidelines for alendronate. BOX 44.9 Patient Teaching Guidelines for Alendronate Take tablets on waking only with 6 to 8 oz of water or more at least 30 minutes before eating or drinking anything else, including food, beverages, or other drugs. Waiting longer than 30 minutes improves absorption. Do not lie down for at least 30 minutes after taking alendronate to reduce the risk of esophageal irritation and aid movement of the drug to the stomach. Report adverse effects to the health care provider immediately, especially esophageal pain, irritation, or burning; heartburn; dyspepsia, nausea, or vomiting; or difficulty swallowing. Other Drugs in the Class Other bisphosphonates include ibandronate (Boniva), pamidronate (Aredia), risedronate (Actonel), and zoledronic acid (Reclast, Zometa). Ibandronate, risedronate, and zoledronic acid (Reclast), like alendronate, are used to prevent and treat osteoporosis. Both ibandronate and risedronate are available in oral preparations to be taken once monthly. Zoledronic acid, as Reclast, is administered IV once a year. Pamidronate is not approved by the U.S. Food and Drug Administration (FDA) for osteoporosis but may be useful for various bone-related conditions such as Paget’s disease and bone lesions. Common adverse effects of bisphosphonates include nausea and vomiting. Serious adverse effects may include anemia, jaw osteonecrosis, neutropenia, infections, and renal damage. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvrN… 9/10 11/27/23, 4:52 AM Realizeit for Student Other Medications Used to Treat Bone Disorders and Hypercalcemia Calcitonin (Miacalcin) is used in the treatment of hypercalcemia, Paget’s disease, and postmenopausal osteoporosis. In hypercalcemia, calcitonin lowers serum calcium levels by inhibiting bone resorption. Calcitonin is most likely to be effective in hypercalcemia caused by hyperparathyroidism, prolonged immobilization, or certain malignant neoplasms. In acute hypercalcemia, health care providers may use calcitonin along with other measures to lower serum calcium rapidly. A single injection of calcitonin decreases serum calcium levels in approximately 2 hours, and its effects last approximately 6 to 8 hours. In Paget’s disease, calcitonin slows the rate of bone turnover, improves bone lesions on radiologic examination, and relieves bone pain. In osteoporosis, calcitonin prevents further bone loss in the presence of adequate calcium and vitamin D. Denosumab (Prolia, Xgeva) is an antiresorptive drug. Prolia is used to treat osteoporosis in postmenopausal women at high risk of fracture. Xgeva is used to prevent skeletal-related events in bone metastases from solid tumors. Denosumab decreases bone resorption and increases bone mass and strength. The drug is administered subcutaneously at 6-month intervals. Adverse effects include fatigue, weakness, back pain, extremity pain, hypocalcemia, hypophosphatemia, nausea, diarrhea, peripheral edema, hypertension, headache, skin rash, and dermatitis. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=0Dn26kXyU%2f6F5gOCz4%2f2IT%2f2%2bt0zmWpgA%2fttBl%2bYliu9txYeiNyhjGIrXvr… 10/10