Ppt chapter 50

Chapter 50
Drugs Affecting Pituitary,
Thyroid, Parathyroid, and
Hypothalamic Function
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

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.)
• 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

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.)
• 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
• 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
• 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.)
• 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
• 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
• 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.)
• 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 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
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.

Question
• 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
• 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
• 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
– 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.)
– 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
• 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
• 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
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
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.

Question
• 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

Answer
• 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 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
– 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.)
– 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
• 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
• 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
adverse reactions to thyroid hormone replacement.

Levothyroxine: Nursing Diagnoses and
Outcomes (cont.)
• Risk for Injury related to preexisting health status that
requires cautious use of a thyroid agent
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 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 Evaluation
– Explain the purpose of drug therapy.
– Advise patients to avoid OTC drugs.
– In patients taking levothyroxine, monitor serum
thyroid hormone levels periodically.

Question
• Levothyroxine is a Pregnancy Category ___ drug?
– A. A
– B. B
– C. C
– D. D
– E. X

Answer
• 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
• 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
– Palliative treatment of hyperthyroidism
– Administered: oral. Metabolism: liver. Excreted:
kidneys.
– Inhibits the synthesis of thyroid hormones

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
• 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
• 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.)
• 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 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
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
• Methimazole is a Pregnancy Category _____ drug.
– A. A
– B. B
– C. C
– D. D
– E. X

Answer
• D. D
• Rationale: Methimazole is a Pregnancy Category D drug.

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
– 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.)
– 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
• 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
• 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 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
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.

Question
• When calcitonin is administered with vitamin D, there is
an increase in the therapeutic effect of calcitonin?
– A. True
– B. False

Answer
• 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
• 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.)
• 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
– 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.)
– 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
• 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
• 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 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
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
• Calcitriol dosing guidelines are established for all age
groups.
– A. True
– B. False

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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