Thyroid & Parathyroid Agents Flashcards
What are the actions of the Thyroid gland?
- Produces two thyroid hormones using iodine found in the diet:
- Tetraiodothyronine or levothyroxine (T4)
-Triiodothyronine or liothyronine (T3)
Removes iodine from the blood, concentrates it, and prepares it for attachment to tyrosine, an amino acid.
What are the function of Thyroid Hormones (TH) ?
- Regulate the rate of metabolism
- Affect heat production and body temperature
- Affect oxygen consumption, cardiac output, and blood volume
- Affect enzyme system activity
- Affect metabolism of carbohydrates, fats, and proteins
- Regulate growth and development
What are the two types of Thyroid Dysfunction?
Hypothyroidism (underactive) & Hyperthyroidism (overactive)
Explain Hypothyroidism.
- Causes:
Absence of the thyroid gland
Lack of sufficient iodine in the diet to produce the needed level of thyroid hormone
Lack of sufficient functioning thyroid tissue due to tumor or autoimmune disorders
Lack of TRH (Thyroid Releasing Hormone) related to a tumor or disorder of the hypothalamus
Lack of TSH (Thyroid Stimulating Hormone) due to pituitary disease - Signs & symptoms- can be varied and vague, such as obesity and fatigue
Explain Hyperthyroidism.
- Definition : Excessive amounts of thyroid hormones are produced and released into the circulation
- Cause : Graves’ disease
- Signs and Symptoms : Increased body temperature, tachycardia, thin skin, palpitations, hypertension, flushing, intolerance to heat, amenorrhea, weight loss, and goiter
What are some lifespan considerations that we need to take into account when giving Thyroid and Parathyroid agents to children?
Hypothyroidism: Levothyroxine
Higher doses
Monitor thyroid labs
Monitor growth and development
Hyperthyroidism : Methimazole
Don’t use: Propylthiouracil
Radioactive agents
Hypercalcemia
Rare
Bisphosphonates
Monitor calcium levels
What are some lifespan considerations that we need to take into account when giving Thyroid and Parathyroid agents to adults?
Hypothyroidism:
Lifelong
Monitor thyroid labs
Pregnancy and lactation: levothyroxine
Hyperthyroidism:
Side effects worse with methimazole
Sodium iodide can affect fertility
Pregnancy: Propylthiouracil
Do not use in lactation
Hypercalcemia
Osteoporosis
Monitor calcium levels
Calcium and vit D supplements
Pregnancy: Do not use bisphosphonate
What are some lifespan considerations that we need to take into account when giving Thyroid and Parathyroid agents to older adults?
Hypothyroidism :
Screen regularly
Start low, go slow
Levothyroxine
Monitor response: thyroid levels, cardiac effects
- Hyperthyroidism :
Sodium iodide
Monitor for hypothyroidism
Hypercalcemia
Dietary deficiencies: Calcium and vit D supplements
Osteoporosis: Bisphosphonates
Renal impairment
Monitor calcium levels
What are the drug classes that we need to remember for Thyroid Hormones?
- Levothyroxine
- Liothyronine
- Liotrix
- Thyroid Desiccated
How does the Thyroid Hormones work on the body?
Increases cellular metabolism
What are the indications for Thyroid Hormones?
- Hypothyroidism
- Myxedema coma
- Pituitary TSH suppression in the treatment of euthyroid goiters
- Management of thyroid cancer;
- Thyrotoxicosis in conjunction with other therapy
What is an absolute contraindication of Thyroid Hormones?
Allergy
What are some relative contraindication of Thyroid Hormones?
Acute MI
Thyrotoxicosis*
What are some known cautions to consider in relations to Thyroid Hormones?
Hypoadrenal conditions
What are some known adverse reactions to Thyroid Hormones?
- Skin reactions
- Symptoms of hyperthyroidism
- Cardiac stimulation
- CNS effect
Are there any DDI’s to Thyroid Hormones, and if so, what are they?
- Oral anticoagulants
- Digoxin
- Theophylline
Before giving a patient TH, what do we need to assess?
- Hx: cautions/contraindications, family history
- Physical : Assess skin; CNS; vitals & ECG
- Monitor appropriate labs
What nursing diagnosis should we be prepared for before giving TH’s?
- Altered cardiac output
- Malnutrition risk: less than body
requirements - Altered tissue perfusion
- Knowledge deficit
What implementations should we be prepared for when we’ve give a patient TH’s?
- Administration: single daily dose 30-60 minutes before breakfast each day. Administer with a full glass of water. Do not administer other drugs at the same time
- Monitor response carefully when beginning therapy, especially cardiac response.
- Arrange for periodic blood tests
- Patient teaching
What are the Antithyroid Agents that we need to know?
- Thiomides : Propylthiouracil (PTU) & Methimazole
- Iodine Solutions : Strong iodine solution, Potassium iodide & Sodium iodide I131 and I123
Why would you give patients Thiomides ?
For Hyperthyroidism
How does Thiomides work on the body?
Prevent formation of thyroid hormone within the thyroid cells.
Why would you give patients Iodine Solutions ?
- Indication for low dose: diagnosis/evaluate thyroid function
- Indication for high dose: hyperthyroidism, radiation emergencies
How does Iodine Solutions work on the body?
Enters thyroid cells and destroys them by giving off radiation
Why would you give patients Strong iodine solution & potassium iodide ?
hyperthyroidism, radiation emergencies, suppression of thyroid gland before surgery, acute thyrotoxicosis.
