Thyroid and Parathyroid Agents Flashcards
What are the functions of the thyroid gland?
- Regulate 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 nutrient is essential to help produce thyroid hormones?
Iodine
Hypothyroidism
Causes, S/S
Causes:
* Absence of a 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 a tumor or autoimmune disorders
* Lack of TRH related to tumor or disorder of the hypothalamus
* Lack of TSH due to pituitary disease
Signs and Symptoms:
* vague
* weight gain
* extreme fatigue
* decreased body temperature
* dry skin
* muscle aches and weakness
* constipation
* intolerance to cold
* Bradycardia
Hyperthyroidism
Causes and S/S
Causes:
* Excessive amounts of thyroid hormones usually caused by Grave’s Disease
Signs and Symptoms:
* Increased body temperature
* Tachycardia
* Bulging Eyes
* Facial Flushing
* Diarrhea
* Tremors
* Increased SBP
* Weight Loss
* Muscle Wasting
Lifespan considerations for Thyroid and Parathyroid Agents
In Children
Hypothyroidism
* USE: Levothyroxine
* Higher doses
* Monitor thyroid labs
* Monitor Growth and Development
Hyperthyroidism:
* USE: Methimazole
* DON’T USE: Propylthiouracil, Radioactive agents
Hypercalcemia:
* Rare
* USE: Biphosphonates
* Monitor Calcium levels
Lifespan considerations for Thyroid and Parathyroid Agents
In Adults
Hypothyroidism:
* Lifelong
* Monitor thyroid levels
* Pregnancy & Lactation: USE: Levothyroxine
Hyperthyroidism:
* Side effects worse with Methimazole
* Sodium Iodide can affect fertility
* Pregnancy: USE Propylthiouracil
* Do NOT use in lactation
Hypercalcemia:
* Osteoporosis
* Monitor calcium levels
* Calcium and Vitamin D supplements
* Pregnancy: Do not use biphosphonates
Lifespan considerations for Thyroid and Parathyroid Agents
In Older Adults
Hypothyroidism:
* Screen regularly
* Start low and go slow
* USE: Levothyroxine
* Monitor response: thyroid levels, cardiac effects
Hyperthyroidism:
* USE: Sodium Iodide (less adv. effects)
* Monitor for hypothyroidism
Hypercalcemia:
* Dietary deficiencies: Calcium and Vit. D. supplements
* Osteoporosis: Biphosphonates
* Renal Impairment
* Monitor calcium levels
Thyroid Hormones
Drug Names
Levothyroxine
Liothyronine
Liotrix
Thyroid Desiccated
Thyroid Hormones
Mechanism of Action
- Increases cellular metabolism in all areas of the body
Thyroid Hormones
Indications
- Hypothyroidism
- Myxedema coma: severe hypothyroidism
- Pituitary TSH suppression in the treatment of euthyroid (normal thyroid) goiters
- Management of thyroid cancer
- Thyrotoxicosis in conjunction with other therapy
Thyroid Hormones
Contraindications
Absolute:
* Allergy
Relative:
* Acute MI
* Thyrotoxicosis - never use by itself
Caution:
* Hypoadrenal conditions
Thyroid Hormones
Adverse Effects
- NONE in correct dose
- Rare: Hair loss
- Symptoms of hyperthyroidism
- Cardiac stimulation
- CNS effects
Thyroid Hormones
Drug Interactions
- Oral anticoagulants: inc. risk of bleeding
- Digoxin: decreased dig levels
- Theophylline: decreased clearance of theophylline w/hypothyroidism - may need to increase theophylline as thyroid hormone levels increase
Thyroid Hormones
Assessment
History:
* Check for allergy, family history, acute MI, thyrotoxicosis, and hypoadrenal conditions
Physical:
* Skin
* CNS
* Vitals
* ECG
Labs:
* Thyroid hormone levels
Thyroid Hormones
Nursing Diagnoses
- Altered Cardiac Output (r/t cardiac effects)
- Malnutrition risk: less than body requirements (r/t changes in metabolism)
- Altered tissue perfusion (r/t thyroid activity)
- Knowledge Deficit
Thyroid Hormones
Implementation/Patient Teaching
- Single daily dose
- Administer 30-60 minutes BEFORE breakfast
- Administer with a full glass of water
- Do not administer other drugs at the same time
- Labs 6 weeks after beginning therapy
- Monitor response closely - especially cardiac response
- Takes several weeks to take effect
- Arrange for periodic blood tests
Antithyroid Agents
Drug Names
Thiomides:
* Propylthiouracil (PTU)
* Methimazole
Iodine Solutions:
* Stong iodine solution
* Potassium iodide
* Sodium iodide I(131) and I(132)