Download Synthetic thyroid hormone T 4

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Secretes three hormones essential for proper
regulation of metabolism
◦ Thyroxine (T4)
◦ Triiodothyronine (T3)
◦ Calcitonin
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Located near the parathyroid gland
◦ Which is responsible for maintaining adequate levels of
calcium in the extracellular fluid
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Primary: abnormality in the thyroid gland
itself
Secondary: results when the pituitary gland is
dysfunctional and does not secrete TSH
Tertiary: results when the hypothalamus
gland does not secrete TRH, which stimulates
the release of TSH
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Cretinism
◦ Hyposecretion of thyroid hormone during youth
◦ Leads to cretinism: low metabolic rate, retarded
growth and sexual development, possibly mental
retardation
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Myxedema
◦ Hyposecretion of thyroid hormone during
adulthood
◦ Decreased metabolic rate, loss of mental and
physical stamina, weight gain, loss of hair, firm
edema, yellow dullness of the skin
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Goiter
◦ Enlargement of the thyroid gland
◦ Results from overstimulation by elevated levels of
TSH
◦ TSH is elevated because there is little or no thyroid
hormone in circulation
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Common symptoms
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Thickened skin
Hair loss
Constipation
Lethargy
Anorexia
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Caused by several diseases
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Graves’ disease
Plummer’s disease (toxic nodular disease)
Multinodular disease
Thyroid storm (induced by stress or infection)
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Affects multiple body systems, resulting in an
overall increase in metabolism
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Diarrhea
Flushing
Increased appetite
Muscle weakness
Sleep disorders
Altered menstrual flow
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Fatigue
Palpitations
 Nervousness
 Heat intolerance
 Irritability
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levothyroxine (Synthroid, Levothyroidl)
◦ Synthetic thyroid hormone T4
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liothyronine (Cytomel)
◦ Synthetic thyroid hormone T3
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liotrix (Thyrolar)
◦ Synthetic thyroid hormone T3-T4 combined
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Thyroid
◦ Desiccated (dried) animal thyroid gland
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Thyroid preparations are given to replace
what the thyroid gland cannot produce to
achieve normal thyroid levels (euthyroid)
Thyroid drugs work the same way as thyroid
hormones
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To treat all three forms of hypothyroidism
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Levothyroxine is the preferred drug because its hormonal
content is standardized; therefore, its effect is predictable
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Thyroid replacement in patients whose thyroid glands have
been surgically removed
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Thyroid replacement when thyroid is destroyed by
radioactive iodine in the treatment of thyroid cancer or
hyperthyroidism
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Cardiac dysrhythmias are the most significant
adverse effect
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May also cause:
◦ Tachycardia, palpitations, angina, hypertension,
insomnia, tremors, headache, anxiety, nausea,
diarrhea, menstrual irregularities, weight loss,
appetite changes, sweating, heat intolerance, others
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Radioactive iodine (I131) works by destroying
the thyroid gland
Surgery to remove all or part of the thyroid
gland
◦ Lifelong thyroid hormone replacement will be
needed
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Antithyroid drugs: thioamide derivatives
◦ methimazole (Tapazole)
◦ propylthiouracil (PTU)
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Used to palliate hyperthyroidism and to
prevent the surge in thyroid hormones that
occurs after the surgical treatment or during
radioactive iodine treatment for
hyperthyroidism
May cause liver and bone marrow toxicity
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Assess for drug allergies, contraindications,
potential drug interactions
Obtain baseline vital signs, weight
Cautious use advised for those with cardiac
disease, hypertension, and pregnant women
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During pregnancy, treatment for
hypothyroidism should continue
Fetal growth may be retarded if maternal
hypothyroidism is untreated during
pregnancy
◦ Adjust dosage every 4 weeks to keep TSH at the
lower end of the normal range
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Teach patient to take thyroid drugs once daily
in the morning to decrease the likelihood of
insomnia if taken later in the day
Teach patient to take the medications at the
same time every day and not to switch brands
without physician approval
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Teach patients to report any unusual
symptoms, chest pain, or heart palpitations
Teach patients not to take OTC medications
without physician approval
Teach patients that therapeutic effects may
take several months to occur
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Antithyroid medications
◦ Better tolerated when given with food
◦ Give at the same time each day to maintain
consistent blood levels
◦ Never stop these medications abruptly
◦ Avoid eating foods high in iodine (seafood, soy
sauce, tofu, and iodized salt)
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Monitor for therapeutic response
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Monitor for adverse effects
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When assessing the older patient, the nurse
keeps in mind that certain non-specfiic
symptoms may represent hypothyroidism n
older patients, such as:
A. Cold intolerance, depression.
B. Leukopenia, anemia.
C. Loss of appetite, polyuria.
D. Weight loss, dry cough.
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When teaching a patient who has a new
prescription for thyroid hormone, the nurse
should instruct the patient to notify the
physician when which adverse effects are
noted?
A. Anxiety.
B. Appetite changes
C. Headache.
D. Palpitations