Parathyroid Agents Nursing Pharmacology and Study Guide

Parathyroid agents are drugs used to treat disorders that affect serum calcium levels. This can be either antihypocalcemic agent or antihypercalcemic agent (further classified into bisphosphonates and calcitonins). The parathyroid glands are four very small groups of glandular tissue located on the back of the thyroid gland. This produce PTH and calcitonin to maintain body’s calcium balance. PTH is the most important regulator of serum calcium levels in the body.

Table of Common Drugs and Generic Names


Here is a table of commonly encountered parathyroid agents, their generic names, and brand names:

Classification Generic Name Brand Name
Antihypocalcemic Agents calcitriol Rocaltrol
teriparatide Forteo
Antihypercalcemic Agents
  • Bisphosphonates
alendronate Fosamax
  • Calcitonin
calcitonin salmon Miacalcin, Fortical

Disease Spotlight: Parathyroid Dysfunction


  • Parathyroid dysfunction involves either absence of PTH (hypoparathyroidism) or overproduction of PTH (hyperparathyroidism). This can affect any age group.
  • Hypoparathyroidism is a rare condition characterized by absence of PTH resulting to low calcium level (hypocalcemia). Accidental removal of parathyroid glands during surgery mostly cause this condition.
  • Hyperparathyroidism is a condition characterized by excessive production of PTH leading to elevated calcium level (hypercalcemia). Primary hyperparathyroidism occurs more often in women between 60-70 years of age. Secondary hyperparathyroidism occurs most frequently in patients with chronic renal failure.
  • Paget’s disease is a genetically linked disorder characterized by overactive osteoclasts that are eventually replaced by enlarged and softened bony structures. Manifestations include deep bone pain, headaches, and hearing loss.
  • Postmenopausal osteoporosis occur when dropping levels of estrogen allow calcium to be pulled out of the bone, resulting in a weakened and honeycombed bone structure.

Antihypocalcemic Agents


  • Antihypocalcemic agents are drugs used to treat deficient levels of PTH.

Therapeutic Action

The desired and beneficial action of antihypocalcemic agents:

  • a vitamin D compound that regulates the absorption of calcium and phosphate from the small intestine, mineral resorption in bone, and reabsorption of phosphate from renal tubules, increasing the serum calcium level.
  • Teriparatide stimulates new bone formation leading to increase in skeletal mass. It increases serum calcium and decreases serum phosphorus.

Indications

Antihypocalcemic agents are indicated for the following medical conditions:

  • Management of hypocalcemia in patients on chronic renal dialysis
  • Management of hypocalcemia associated with hypoparathyroidism and with sustained systemic glucocorticoids therapy

Pharmacokinetics

Here are the characteristic interactions of antihypocalcemic agents and the body in terms of absorption, distribution, metabolism, and excretion:

Route Onset Peak Duration
PO Slow 4 h 3-5 d
T1/2: 5-8 h
Metabolism: liver
Excretion: bile

Contraindications and Cautions

The following are contraindications and cautions for the use of antihypocalcemic agents:

  • Allergy to any component of the drug. To prevent hypersensitivity reactions.
  • Hypercalcemia or Vitamin D toxicity. Can be exacerbated by drug effects.
  • Pregnancy and lactation. Potential adverse effects to the fetus. Calcitriol has been associated with hypercalcemia in the baby when used by nursing mothers.
  • Teriparatide is associated with osteosarcoma in animal studies.

Adverse Effects

Use of antihypocalcemic agents may result to these adverse effects:

  • CNS: weakness, headache, somnolence, irritability
  • GI: metallic taste, nausea, vomiting, dry mouth, constipation

Interactions

The following are drug-drug interactions involved in the use of antihypocalcemic agents:

  • Magnesium-containing antacids. Risk for hypermagnesemia.
  • Cholestyramine or mineral oil. Reduced absorption of antihypocalcemic agents; separate for at least two hours.

Nursing Considerations

Here are important nursing considerations when administering antihypocalcemic agents:

Nursing Assessment

These are the important things the nurse should include in conducting assessment, history taking, and examination:

  • Assess for contraindications or cautions (e.g. history of allergy, renal stone, pregnancy, etc.) to avoid adverse effects.
  • Assess skin lesions; orientation and affect; liver evaluation; serum calcium, magnesium, and alkaline phosphate levels; and radiographs of bones as appropriate, to determine baseline status before beginning therapy and for any potential adverse effects.
Nursing Diagnoses

Here are some of the nursing diagnoses that can be formulated in the use of this drug for therapy:

Implementation with Rationale

These are vital nursing interventions done in patients who are taking antihypocalcemic agents:

  • Monitor serum calcium concentration before and periodically during treatment to allow for adjustment of dose to maintain calcium levels within normal limit.
  • Provide supportive measures (e.g. analgesics, small and frequent meals, help with activities of daily living) to help patient deal with CNS and GI effects of the drug.
  • Arrange for nutritional consultation if GI effects are severe to ensure nutritional balance.
  • Provide patient education about drug effects and warning signs to report to enhance patient knowledge and to promote compliance.
Evaluation

Here are aspects of care that should be evaluated to determine effectiveness of drug therapy:

  • Monitor patient response to therapy (return of serum calcium levels to normal).
  • Monitor for adverse effects (weakness, headache, GI effects).
  • Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
  • Monitor patient compliance to drug therapy.

Antihypercalcemic Agents


  • Antihypercalcemic agents are drugs used to treat PRH excess or hypercalcemia. These agents include bisphosphonates and calcitonin salmon.
  • These drugs act on the serum levels of calcium and do not suppress the parathyroid gland or PTH.

Therapeutic Action

The desired and beneficial action of antihypercalcemic agents:

  • Bisphosphonates slow normal and abnormal bone resorption without inhibiting bone formation and mineralization.
  • Calcitonin inhibits bone resorption and lowers elevated serum calcium. It also increases the excretion of filtered phosphate, calcium, and sodium by the kidney.

Indications

Antihypercalcemic agents are indicated for the following medical conditions:

  • Bisphosphonate is used to treat and prevent osteoporosis in postmenopausal women and in men. It is also used to treat glucocorticoid-induced osteoporosis as well as to treat Paget’s disease.
  • Calcitonin is used for treatment of Paget’s disease, postmenopausal osteoporosis, and emergency treatment of hypercalcemia.

Pharmacokinetics

Here are the characteristic interactions of biphosphonates and the body in terms of absorption, distribution, metabolism, and excretion:

Route Onset Peak Duration
PO Slow Days
T1/2: >10 days
Metabolism: not metabolized
Excretion: urine

 

Here are the characteristic interactions of calcitonin and the body in terms of absorption, distribution, metabolism, and excretion:

Route Onset Peak Duration
IM, subcutaneous 15 min 3-4 h 8-24 h
Nasal Rapid 31-39 min 8-24 h
T1/2: 1.43 h
Metabolism: kidneys
Excretion: urine

Contraindications and Cautions

The following are contraindications and cautions for the use of antihypercalcemic agents:

  • Allergy to any component of the drug. To prevent hypersensitivity reactions.
  • Hypocalcemia. Worsened by calcium-lowering effect of bisphosphonates
  • Pregnancy and lactation. Potential adverse effects to fetus or neonate
  • Renal dysfunction. Can alter drug excretion.
  • Upper GI disease. Can be aggravated by bisphosphonates. Drug should be taken with a full glass of water and patient should stay upright for 30 minutes because serious esophageal erosion can occur.
  • Allergy to salmon or fish products. To prevent hypersensitivity reaction with taking calcitonin
  • Pernicious anemia. Can be worsened by calcitonin

Adverse Effects

Use of antihypercalcemic agents may result to these adverse effects:

  • Bisphosphonates: headache, nausea, diarrhea
  • Calcitonins: flushing of the face and hands, skin rash, nausea and vomiting, urinary frequency, and local inflammation at the site of injection

Interactions

The following are drug-drug interactions involved in the use of antihypercalcemic agents:

  • Bisphosphonates. Decreased absorption if with iron, antacids, or multiple vitamins so separate by at least 30 minutes; GI distress with aspirin.
  • There is no clinically important drug-drug interaction with calcitonin.

Nursing Considerations

Here are important nursing considerations when administering antihypercalcemic agents:

Nursing Assessment

These are the important things the nurse should include in conducting assessment, history taking, and examination:

  • Assess for contraindications or cautions (e.g. history of allergy to drug or to fish products with salmon calcitonin, renal dysfunction, pregnancy and lactation, etc.) to avoid adverse effects.
  • Assess skin lesions; orientation and affect; abdominal examination; serum electrolytes; and renal function tests, to determine baseline status before beginning therapy and for any potential adverse effects.
Nursing Diagnoses

Here are some of the nursing diagnoses that can be formulated in the use of this drug for therapy:

Implementation with Rationale

These are vital nursing interventions done in patients who are taking antihypercalcemic agents:

  • Ensure adequate hydration with any of these agents to reduce risk of renal complications.
  • Arrange for concomitant vitamin D, calcium supplements, and hormone replacement therapy if used to treat postmenopausal osteoporosis.
  • Rotate injection sites and monitor for inflammation if using calcitonins to prevent tissue breakdown and irritation.
  • Monitor serum calcium before and periodically during treatment to allow for dose adjustment.
  • Arrange for periodic blood tests of renal function if using gallium to monitor for renal dysfunction.
  • Provide comfort measures to help patient cope with drug effects.

Provide patient education about drug effects and warning signs to report to enhance patient knowledge and to promote compliance.

Evaluation

Here are aspects of care that should be evaluated to determine effectiveness of drug therapy:

  • Monitor patient response to therapy (return of calcium levels to normal level; preventions of complications of osteoporosis; control of Paget’s disease).
  • Monitor for adverse effects (skin rash, nausea and vomiting, renal dysfunction).
  • Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
  • Monitor patient compliance to drug therapy.

Practice Quiz: Parathyroid Agents


Here are some practice questions for this study guide:

Exam Mode

In Exam Mode: All questions are shown but the results, answers, and rationales (if any) will only be given after you’ve finished the quiz.

Practice Quiz: Parathyroid Agents

Start
Congratulations - you have completed Practice Quiz: Parathyroid Agents. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%
Your answers are highlighted below.

Practice Mode

Practice Mode: This is an interactive version of the Text Mode. All questions are given in a single page and correct answers, rationales or explanations (if any) are immediately shown after you have selected an answer. No time limit for this exam.

Practice Quiz: Parathyroid Agents

Start
Congratulations - you have completed Practice Quiz: Parathyroid Agents. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%
Your answers are highlighted below.

Text Mode

Text Mode: All questions and answers are given on a single page for reading and answering at your own pace. Be sure to grab a pen and paper to write down your answers.

1. Hyperparathyroidism

A. Leads to low serum level of calcium has a primary form which is more common in elderly men
B. Has a primary form which is more common in elderly men
C. Benefits from antihypercalcemic agents
D. Secondary form is common in patients with chronic liver failure

1. Answer: C. Benefits from antihypercalcemic agents

Hyperparathyroidism is a condition characterized by excessive production of PTH leading to elevated calcium level (hypercalcemia). Therefore, it will benefit from antihypercalcemic agents. Primary hyperparathyroidism occurs more often in women between 60-70 years of age. Secondary hyperparathyroidism occurs most frequently in patients with chronic renal failure.

2. A patient taking calcitriol is also prescribed with a magnesium-containing antacid. Which of the following should be included in the nurse’s monitoring?

A. Color of stool
B. Signs of bleeding
C. Liver function test
D. Serum electrolyte level

2. Answer: D. Serum electrolyte level

Antihypocalcemic agents combined with magnesium-containing antacids increase the risk for hypermagnesemia. Therefore, it is important to monitor serum magnesium level.

3. Which of the following should be included in patient teaching of patients taking bisphosphonates?

A. Stay upright 30 minutes after taking the drug.
B. Take drug on empty stomach.
C. Chew drug instead of swallowing.
D. Both B and C

3. Answer: A. Stay upright 30 minutes after taking the drug.

Drug should be taken with a full glass of water and patient should stay upright for 30 minutes because serious esophageal erosion can occur.

4. Common adverse effects of calcitonin include:

A. Headache
B. Flushing of the face and hands
C. Abdominal tenderness
D. Diarrhea

4. Answer: B. Flushing of the face and hands

Calcitonin is available in IM, subcutaneous, and nasal forms. Other adverse effects include skin rash, nausea and vomiting, urinary frequency, and local inflammation at the site of injection. Headache and diarrhea are common in bisphosphonates.

5. This is a genetically-linked condition with parathyroid dysfunction characterized by deep bone pain, headaches, and hearing loss.

A. Tay-Sachs disease
B. Paget’s disease
C. Gaucher disorder
D. Marfan Syndrome

5. Answer: B. Paget’s disease

Paget’s disease is a genetically linked disorder characterized by overactive osteoclasts that are eventually replaced by enlarged and softened bony structures. Manifestations include deep bone pain, headaches, and hearing loss.

See Also


Here are other nursing pharmacology study guides:

Endocrine System Drugs

Autonomic Nervous System Drugs

Immune System Drugs

Chemotherapeutic Agents

Reproductive System Drugs

Nervous System Drugs

Cardiovascular System Drugs

Further Reading and Resources


Recommended resources and books:

  1. Focus on Nursing Pharmacology - Easy to follow guide for Pharmacology
  2. NCLEX-RN Drug Guide: 300 Medications You Need to Know for the Exam - Great if you're reviewing for the NCLEX
  3. Nursing 2017 Drug Handbook (Nursing Drug Handbook) - Reliable nursing drug handbook!
  4. Lehne's Pharmacology for Nursing Care - Provides key information on commonly used drugs in nursing
  5. Pharmacology and the Nursing Process - Learn how to administer drugs correctly and safely!
  6. Pharm Phlash Cards!: Pharmacology Flash Cards - Flash Cards for Nursing Pharmacology