ppt chapter 50

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 50

Drugs Affecting Pituitary, Thyroid, Parathyroid, and

Hypothalamic Function

Chapter 50

Drugs Affecting Pituitary, Thyroid, Parathyroid, and

Hypothalamic Function


Physiology Physiology

• Pituitary gland function

– Anterior lobe of the pituitary gland: It controls the function of glucocorticoid hormone levels (ACTH), body growth and metabolism (GH), function of the thyroid gland (TSH), gonadal function (FSH and LH), and milk production and breast growth (prolactin).

– Posterior lobe of the pituitary gland: It stores and secretes two effector hormones (hormones that produce an effect when stimulated): oxytocin and vasopressin (also known as antidiuretic hormone [ADH]).


Physiology (cont.)Physiology (cont.)

• Thyroid gland function

– It controls cellular metabolism and promotes normal growth and development.

• Parathyroid gland function

– PTH affects three target organs: bone, kidneys, and GI tract.

– The major controlling factor for PTH secretion is serum calcium.


Hypothalamus Hypothalamus


Pathophysiology Pathophysiology

• Anterior pituitary gland dysfunction: It includes growth hormone deficiency and excess.

• Posterior pituitary gland dysfunction: Major disorders are diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone (SIADH).

• Thyroid gland dysfunction: Hyperfunctioning or hypofunctioning gland, malfunctions that may be caused by either a congenital defect or by a problem that occurs later in life.


Pathophysiology (cont.)Pathophysiology (cont.)

• Parathyroid gland dysfunction: Hormone is a major regulator of serum calcium and phosphate.

– A decrease in serum calcium concentration is the dominant regulator of PTH, with a response rate of just a few seconds.

– A decrease in phosphate causes an indirect effect on PTH by combining with calcium and decreasing serum calcium concentrations.


Growth Hormones Growth Hormones

• GH deficiency, leading to short stature, was initially treated with GH injections extracted from the pituitary glands of cadavers.

• Presently, synthetic human GH (rhGH), produced from recombinant DNA, is available.

• rhGH therapy is very expensive.

• Prototype drug: somatropin


Somatropin: Core Drug Knowledge Somatropin: Core Drug Knowledge

• Pharmacotherapeutics

– Used as long-term replacement of inadequate endogenous GH secretion

• Pharmacokinetics

– Administered: SC and IM. Excreted: liver and kidneys.

• Pharmacodynamics

– It stimulates cell growth and cellular mitosis, facilitates cellular uptake of amino acids for protein synthesis, and promotes use of fatty acids for energy.


Somatropin: Core Drug Knowledge (cont.)Somatropin: Core Drug Knowledge (cont.)

• Contraindications and precautions

– Growth promotion in children with closed epiphyses

• Adverse effects

– Headache, hypertension, joint and back pain, peripheral edema, muscle aches, and rhinitis

• Drug interactions

– Anabolic steroids, androgens, estrogens, or thyroid hormones may accelerate epiphyseal maturation.


Somatropin: Core Patient Variables Somatropin: Core Patient Variables

• Health status

– Assess medical history and contraindications to the drug.

• Life span and gender

– Pregnancy Category C drug

• Lifestyle, diet, and habits

– Assess ability to adhere to medical regimen.

• Environment

– Assess the environment where the drug will be given.


Somatropin: Nursing Diagnoses and Outcomes Somatropin: Nursing Diagnoses and Outcomes

• Delayed Growth and Development related to deficiency of GH secretion

– Desired outcome: The patient will demonstrate an increase in linear growth.

• Imbalanced nutrition: More (or Less) than Body Requirements related to endocrine changes and rapid changes in height and weight

– Desired outcome: The patient will receive adequate nutrition for growth appropriate to age and need.


Somatropin: Nursing Diagnoses and Outcomes (cont.)Somatropin: Nursing Diagnoses and Outcomes (cont.)

• Impaired Tissue Integrity related to pain and swelling at injection site

– Desired outcome: The patient will not experience pain and swelling at the injection site.

• Altered Comfort related to headache, joint and muscle discomfort, secondary to somatropin effects

– Desired outcome: The patient will describe measures to improve comfort.


Somatropin: Planning and InterventionsSomatropin: Planning and Interventions

• Maximizing therapeutic effects

– Hypothyroidism may develop during somatropin therapy.

– Patients who require chronic cycling peritoneal dialysis should receive their doses of somatropin in the morning, after the dialysis is completed.

• Minimizing adverse effects

– GH therapy may induce insulin resistance.

– Be alert for the development of a limp or complaints of hip or knee pain, and tell parents to do the same.


Somatropin: Teaching, Assessment, and EvaluationSomatropin: Teaching, Assessment, and Evaluation

• Patient and family education

– Explain that this drug is replacing an important hormone (GH).

– Explain proper administration of medication.

• Ongoing assessment and evaluation

– In patients taking somatropin, evaluate thyroid function at regular intervals because hypothyroidism compromises rGH drug effects.


QuestionQuestion

• Patients taking somatropin should have which lab values monitored on a routine basis due to adverse effects of the drug therapy?

– A. TSH

– B. CBC

– C. Glucose level

– D. Both A and C

– E. All of the above


Answer Answer

• D. Both A and C

• Rationale: Somatropin can cause hypothyroidism and glucose intolerance; therefore, these lab values should be monitored during therapy.


Posterior Pituitary Hormone Regulators Posterior Pituitary Hormone Regulators

• The posterior pituitary stores two hormones that are produced in the hypothalamus: vasopressin and oxytocin.

• Desmopressin and vasopressin are synthetic analogues of the naturally occurring posterior pituitary hormone.

• Prototype drug: desmopressin


Desmopressin: Core Drug Knowledge Desmopressin: Core Drug Knowledge


– Manages central DI and nocturnal enuresis and maintains homeostasis in hemophilia A


– Administered: intranasally, orally, or parenterally (IV or SC route). Metabolism: liver. Excreted: kidneys.


– Interacts with V1 and V2 receptors


Desmopressin: Core Drug Knowledge (cont.)Desmopressin: Core Drug Knowledge (cont.)


– Hypersensitivity

• Adverse effects

– Abdominal pain, transient headache, nasal congestion, nausea, rhinitis, and facial flushing


– Carbamazepine, chlorpromazine, and nonsteroidal anti-inflammatory drugs


Desmopressin: Core Patient Variables Desmopressin: Core Patient Variables

• Health status

– Assess for conditions that require drug therapy.


– Pregnancy Category B drug


– Assess lifestyle activities and use of recreational drugs.

• Environment



Desmopressin: Nursing Diagnoses and Outcomes Desmopressin: Nursing Diagnoses and Outcomes

• Risk for Fluid Volume Excess related to administration of desmopressin, secondary to diabetes insipidus

– Desired outcome: The patient will not demonstrate signs and symptoms of water intoxication and will maintain urine specific gravity within a normal range.

• Risk for Ineffective Therapeutic Regimen Management related to lack of knowledge of diabetes insipidus, disease management, and signs and symptoms of complications

– Desired outcome: The patient will describe the disease process, causes, and factors contributing to symptoms and the regimen for disease or symptom control, relate intent to practice health behaviors needed or desired to control disease and prevent complications, and report less anxiety from fear of the unknown and loss of control.


Desmopressin: Planning and InterventionsDesmopressin: Planning and Interventions


– Establish baseline values for weight, blood pressure, electrolytes, and urine specific gravity.

– Protect ADH solutions from agitation and temperature extremes.


– Assess the patient for preexisting cardiovascular or renal disorders and monitor patients carefully for cardiac reactions from desmopressin.


Desmopressin: Teaching, Assessment, and EvaluationDesmopressin: Teaching, Assessment, and Evaluation


– Provide information about drug therapy.

– Alcohol can alter the therapeutic response to desmopressin.


– Instruct patients taking desmopressin to monitor urine specific gravity and intake and output as well as to weigh themselves daily to determine drug efficacy.


QuestionQuestion

• Desmopressin is used to treat

– A. Central DI

– B. Primary nocturnal enuresis

– C. Hemophilia A

– D. Both A and B

– E. All of the above


AnswerAnswer

• E. All of the above

• Rationale: Desmopressin is used to manage central DI. Primary nocturnal enuresis and episodes of spontaneous or trauma-induced bleeding. Parenteral desmopressin maintains homeostasis in hemophilia A and von Willebrand disease (type I).


Thyroid Drugs Thyroid Drugs

• Thyroid hormones influence essentially every organ system in the body.

• Thyroid disorders involve an alteration in the quantity of thyroid hormone secretion, enlargement of the thyroid gland (goiter), or both and are classified as either hyperthyroidism or hypothyroidism.

• Hypothyroidism may be mistaken for the normal aging process.

• The only treatment for hypothyroidism is lifelong replacement of thyroid hormones that are adequate to meet the individual’s metabolic needs.

• Prototype drug: levothyroxine (T4; Levothroid, Synthroid)


Levothyroxine: Core Drug Knowledge Levothyroxine: Core Drug Knowledge


– Used as replacement therapy in hypothyroidism


– Administered: oral. Metabolism: liver. Excreted: bile. Onset: 6 to 8 hours.


– Acts as replacement for natural thyroid hormone


Levothyroxine: Core Drug Knowledge (cont.)Levothyroxine: Core Drug Knowledge (cont.)


– Hypersensitivity, thyrotoxicosis, and acute MI complicated by hypothyroidism

• Adverse effects

– Hypertension, tachycardia, arrhythmias, anxiety, headache, nervousness, GI irritation, sweating, and heat intolerance


– Many drugs


Levothyroxine: Core Patient Variables Levothyroxine: Core Patient Variables

• Health status

– Assess for contraindications to therapy.


– Pregnancy Category A drug


– Assess the ability to adapt to long-term therapy.

• Environment



Levothyroxine: Nursing Diagnoses and Outcomes Levothyroxine: Nursing Diagnoses and Outcomes

• Imbalanced nutrition: More than Body Requirements related to dietary intake in excess of metabolic demands secondary to hypothyroidism

– Desired outcome: The patient will maintain normal body weight, describe reasons why weight gain may occur, discuss nutritional needs related to age, lifestyle, and diagnosis, and discuss the effects of exercise and diet on weight control.

• Risk for Injury related to adverse drug reactions

– Desired outcome: The patient will not experience adverse reactions to thyroid hormone replacement.


Levothyroxine: Nursing Diagnoses and Outcomes (cont.)Levothyroxine: Nursing Diagnoses and Outcomes (cont.)

• Risk for Injury related to preexisting health status that requires cautious use of a thyroid agent

– Desired outcome: The patient will not experience complications of preexisting health conditions.

• Knowledge Deficit related to thyroid dysfunction and the necessity for thyroid hormone replacement

– Desired outcome: The patient and family will express accurate understanding of the teaching regarding the disease process and the prescribed thyroid hormone replacement therapy.


Levothyroxine: Planning and InterventionsLevothyroxine: Planning and Interventions


– Replacement therapy is a lifelong occurrence.

– During drug therapy, monitor cardiovascular response and serum thyroid function.


– Young adults without evidence of coronary artery disease can begin a full replacement dose of levothyroxine.


Levothyroxine: Teaching, Assessment, and EvaluationLevothyroxine: Teaching, Assessment, and Evaluation


– Explain the purpose of drug therapy.

– Advise patients to avoid OTC drugs.


– In patients taking levothyroxine, monitor serum thyroid hormone levels periodically.


QuestionQuestion

• Levothyroxine is a Pregnancy Category ___ drug?

– A. A

– B. B

– C. C

– D. D

– E. X


AnswerAnswer

• A. A

• Rationale: Levothyroxine is in Pregnancy Category A.

• Thyroid hormone deficiency may have an adverse effect on fetal nervous system development and on the outcome of the pregnancy.


Antithyroid Compounds Antithyroid Compounds

• Hyperthyroidism is treated with thyroid-hormone antagonist drugs, surgery, or radioactive iodine.

• The purpose of treatment is to reduce the amount of functional thyroid tissue.

• Prototype drug: methimazole (MMI)


Methimazole: Core Drug Knowledge Methimazole: Core Drug Knowledge


– Palliative treatment of hyperthyroidism


– Administered: oral. Metabolism: liver. Excreted: kidneys.


– Inhibits the synthesis of thyroid hormones


Methimazole: Core Drug Knowledge (cont.)Methimazole: Core Drug Knowledge (cont.)


– Hypersensitivity

• Adverse effects

– Hives, itching, rash, fever, arthralgia, joint swelling, vertigo, drowsiness, nausea and vomiting, and altered taste sensation


– Beta-blocking agents, theophylline, and warfarin


Methimazole: Core Patient Variables Methimazole: Core Patient Variables

• Health status

– Assess for contraindications to therapy.


– Pregnancy Category D drug


– Assess the ability to adapt to long-term therapy.

• Environment



Methimazole: Nursing Diagnoses and Outcomes Methimazole: Nursing Diagnoses and Outcomes

• Imbalanced nutrition: Less than Body Requirements related to increased metabolic demands secondary to hypothyroidism

– Desired outcome: The patient will describe reasons why weight loss may occur and discuss nutritional needs related to age, lifestyle, and diagnosis.

• Risk for Injury related to blood dyscrasias (e.g., granulocytosis) or to drowsiness and vertigo secondary to adverse reactions of PTU

– Desired outcome: The patient will demonstrate no adverse hematologic reactions to thyroid therapy.


Methimazole: Nursing Diagnoses and Outcomes (cont.)Methimazole: Nursing Diagnoses and Outcomes (cont.)

• Nonadherence related to long-term use of the antithyroid agent and need to take the prescribed medication frequently

– Desired outcome: The patient will describe the reasons for the therapeutic regimen, identify barriers to adherence, and identify the behaviors that must change to facilitate adherence.


Methimazole: Planning and InterventionsMethimazole: Planning and Interventions


– Ensure that the drug is being administered appropriately.


– During drug therapy, arrange for periodic blood tests to monitor for hematologic and thyroid functions.

– Monitor the patient’s bone marrow function.


Methimazole: Teaching, Assessment, and EvaluationMethimazole: Teaching, Assessment, and Evaluation


– Explain the purpose of therapy.

– If the drug is taken in divided doses, instruct patients to take them every 8 hours around the clock.


– Monitor serum thyroid hormone levels periodically to evaluate the effectiveness of MMI and to assess the need for replacement thyroid hormone because the thyroid gland is suppressed.


Question Question

• Methimazole is a Pregnancy Category _____ drug.

– A. A

– B. B

– C. C

– D. D

– E. X


Answer Answer

• D. D

• Rationale: Methimazole is a Pregnancy Category D drug.


Antihypercalcemic, Calcium-Regulator Drugs Antihypercalcemic, Calcium-Regulator Drugs

• Antihypercalcemic drugs do not directly affect the parathyroid gland or PTH but rather inhibit bone resorption of calcium.

• These agents are frequently used in the treatment of Paget disease.

• Individuals with symptomatic disease experience bone pain and deformity, fractures, spinal cord compression, or cranial and spinal cord entrapment.

• Prototype drug: calcitonin


Calcitonin: Core Drug Knowledge Calcitonin: Core Drug Knowledge


– Treatment of symptomatic Paget disease


– Administered: SC, IM, or intranasal. Metabolism: kidneys. Excreted: kidneys.


– A synthetic polypeptide with essentially the same actions as calcitonin


Calcitonin: Core Drug Knowledge (cont.)Calcitonin: Core Drug Knowledge (cont.)


– Allergic to salmon

• Adverse effects

– GI disturbances, skin rash, flushing of the face and hands, and nasal irritation or rhinitis (if using the nasal spray)


– Calcium supplements, antacids, vitamin D, and theophylline


Calcitonin: Core Patient Variables Calcitonin: Core Patient Variables

• Health status

– Determine if the drug can be administered safely.




– Assess the ability to comply with long-term therapy.

• Environment



Calcitonin: Nursing Diagnoses and Outcomes Calcitonin: Nursing Diagnoses and Outcomes

• Imbalanced nutrition: Less than Body Requirements related to GI effects of drug therapy

– Desired outcome: The patient will relate the importance of good nutrition and ingest daily nutritional requirements in accordance with activity level and metabolic needs.

• Pain, Acute or Chronic related to complications of calcium or phosphate imbalances (e.g., renal stones, pathologic fractures, and osteoporosis)

– Desired outcome: The patient will practice pain relief measures to avoid or manage the pain.


Calcitonin: Planning and InterventionsCalcitonin: Planning and Interventions


– Be aware of the proper dosages of calcitonin.

– For Paget disease, it is necessary to give the drug by injection.


– Watch for nausea, which is the most common adverse effect with SC or IM administration.

– Rhinitis, nasal crusts, and dryness are the most common adverse effects of nasal calcitonin.


Calcitonin: Teaching, Assessment, and EvaluationCalcitonin: Teaching, Assessment, and Evaluation


– Instruct patients on proper administration of the drug.

– Explain adverse effects of drug therapy.

– Instruct patients to report twitching, muscle pain, severe diarrhea, or dark urine.


– Calcitonin can cause the serum calcium level to drop, resulting in tetany and cardiac arrhythmias.


QuestionQuestion

• When calcitonin is administered with vitamin D, there is an increase in the therapeutic effect of calcitonin?

– A. True

– B. False


AnswerAnswer

• B. False

• Rationale: If calcitonin, salmon is taken with calcium supplements, antacids, or vitamin D, there is a risk of hypercalcemia, and therapeutic effect is decreased.


Antihypocalcemic Drugs Antihypocalcemic Drugs

• Vitamin D compounds regulate absorption of calcium and phosphate.

• Vitamin D is considered a hormone, although it is not a natural human hormone.

• Vitamin D metabolites control intestinal absorption of dietary calcium, tubular reabsorption of calcium by the kidney, and mobilization of calcium from the skeleton, in conjunction with PTH.


Antihypocalcemic Drugs (cont.)Antihypocalcemic Drugs (cont.)

• Vitamin D is also involved in magnesium metabolism.

• Vitamin D works together with PTH and calcitonin to regulate calcium homeostasis.

• Prototype drug: calcitriol (1,25-dihydroxyvitamin D3, Rocaltrol [capsules, solution], Calcijex [parenteral])


Calcitriol: Core Drug Knowledge Calcitriol: Core Drug Knowledge


– Management of hypocalcemia


– Administered: oral or IV. Metabolism: liver. Excreted: urine and feces.


– Is a fat-soluble vitamin derived from natural sources (fish liver oils) or from conversion of provitamins


Calcitriol: Core Drug Knowledge (cont.)Calcitriol: Core Drug Knowledge (cont.)


– Given carefully to patients at risk for hypercalcemia and hypercalciuria

• Adverse effects

– Weakness, headache, nausea and vomiting, dry mouth, constipation, and bone pain


– Thiazide diuretics


Calcitriol: Core Patient Variables Calcitriol: Core Patient Variables

• Health status

– Assess past medical history and indications for the drug.




– IV doses can be given following dialysis to increase calcium levels.


Calcitriol: Nursing Diagnoses and Outcomes Calcitriol: Nursing Diagnoses and Outcomes

• Imbalanced nutrition: Less than Body Requirements related to reduced absorption of fat-soluble vitamins

– Desired outcome: The patient will ingest a nutritionally balanced diet to allow for normal absorption of fat-soluble vitamins.

• Imbalanced nutrition: More than Body Requirements

– Desired outcome: The patient will identify sources of dietary vitamin D and calcium.

• Acute Pain related to headache and general discomfort secondary to drug effects

– Desired outcome: The patient will not experience undue pain and discomfort as a result of drug therapy.


Calcitriol: Planning and InterventionsCalcitriol: Planning and Interventions


– Calcitriol capsules should be swallowed whole, rather than crushed or chewed.

– When high therapeutic doses are used, frequent serum and urinary calcium, phosphate, and BUN determinations are necessary.


– Chronic dialysis patients should avoid magnesium-containing antacids while taking these drugs.


Calcitriol: Teaching, Assessment, and EvaluationCalcitriol: Teaching, Assessment, and Evaluation


– Explain the purpose of drug therapy.

– Discuss the possible adverse effects of the drug.


– Dosage adjustment is required for patients taking calcitriol as soon as clinical improvement occurs.


Question Question

• Calcitriol dosing guidelines are established for all age groups.

– A. True

– B. False


Answer Answer

• B. False

• Rationale: Dosing guidelines for patients with hypoparathyroidism who are younger than 1 year or patients with pseudohypoparathyroidism who are younger than 6 years have not been established.

ppt chapter 50

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