Thyroid & Parathyroid Agents Flashcards
(129 cards)
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.
Which are the two Thyroid Hormones produced?
Tetraiodothyronine (T4 - ‘tetra means 4) ) & Triiodothyronine (T3 - ‘Tri’ means 3)
What is another name for Tetraiodothyronine ( T4)
Levothyroxine - synthetic
What is another name for Triiodothyronine ( T3)
Liothyronine
Apart from Thyroid Hormone, what other hormone does the Thyroid produce?
Calcitonin
What are the function of Thyroid Hormones (TH) in our body ?
- 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)
Which one is the most common in patients. Hypothyroidism or Hyperthyroidism?
Hypothyroidism.
Explain Hyperthyroidism.
Excessive amounts of thyroid hormones are produced and released into the circulation
* Cause : Graves’ disease - most common cause.
What are the signs and symptoms of hyperthyroidism?
Increased body temperature, tachycardia, thin skin, palpitations, hypertension, flushing, intolerance to heat, amenorrhea (absence of menstrual cycle), weight loss, and goiter (swelling in the neck that occurs when the thyroid gland enlarges due to THS stimulation)
What is the cause of Hypothyroidism?
Causes:
Absence of the thyroid gland either born without it or removed surgically.
Lack of sufficient iodine in the diet to produce the needed level of thyroid hormone
Lack of sufficient functioning of thyroid tissue due to tumor or autoimmune disorders (Hashimoto most common)
Lack of TSH (Thyroid Stimulating Hormone) due to pituitary disease
Lack of TRH (Thyroid Releasing Hormone) related to a tumor or disorder of the hypothalamus
What are the signs and symptoms of Hypothyroidism?
Can be varied and vague, such as obesity and fatigue, weight gain, eyelid edema, feeling cold, hair loss.
What are some lifespan considerations that we need to take into account when giving Thyroid and Parathyroid agents to children?
Hypothyroidism: we will use Levothyroxine
Higher doses - due to higher metabolism.
Monitor thyroid labs
Monitor growth and development
Hyperthyroidism : Methimazole
Don’t use: Propylthiouracil (PTU) or Radioactive agents
Hypercalcemia usually only seen in children with cancer and we can use Bisphosphonates to treat.
Monitor calcium levels closely when using.
What are some lifespan considerations that we need to take into account when giving Thyroid and Parathyroid agents to adults?
Hypothyroidism:
Thyroid replacement therapy is lifelong (Educate)
Levothyroxine is the drug of choice incl pregnancy and lactation.
Hyperthyroidism:
Side effects worse with methimazole such as bone marrow depression, GI and CNS effect.
Sodium iodide can affect fertility.
Pregnancy: Propylthiouracil (PTU) due to less drug passes through the placenta.
Do not use in lactation
Hypercalcemia:
Taken for Osteoporosis
Monitor calcium levels
Pregnancy: Do not use bisphosphonate
What specific condition can happen to the infant if mom is taking Hyperthyroidism agents during pregnancy or lactation ?
Creatininsm
What are some lifespan considerations that we need to take into account when giving Thyroid and Parathyroid agents to older adults?
Hypothyroidism :
Levothyroxine drug of choice.
Screen regularly
Start low, go slow
- Hyperthyroidism :
Sodium iodide usually drug of choice due to less adverse effects.
Monitor for hypothyroidism
Hypercalcemia:
Dietary deficiencies: Calcium and vit D supplements
Osteoporosis: Bisphosphonates can help move calcium back to bone.
Renal impairment
Monitor calcium levels
What are the drug classes that we need to remember for Thyroid Hormones?
- Levothyroxine
- Liothyronine
- Liotrix
- Thyroid Desiccated
Which Thyroid Hormone Agent is made out of dried animal Thyroid tissue, in particular Pig ?
Thyroid Desiccated
How does the Thyroid Hormones work on the body?
Increases the metabolic rate of body tissues which increases oxygen consumption, respirations, heart rate, rate of fat, protein and carbohydrate metabolism. - ultimately affecting our growth and maturation.
Increases cellular metabolism in all areas of our body.
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 Myxedema coma?
Severe hypothyroidism that leads to decreased mental status, hypothermia and other symptoms r/t the functioning and slowing of other organs, It is a medical emergency and there is a high mortality rate associated with it.
What is the difference between Hypothyroidism and Myxedema coma?
With Hyperthyroidism our organisms are still working whereas with Myxedema coma they are starting to not work.
What is Thyrotoxicosis?
A Hyperthyroidism where we see signs and symptoms. We would treat this with hyperthyroid medication to try to stop the negative feedback loop that is increasing the thyroid hormone levels. Decreasing the release of TSH should therefore reduce the TH levels.
To treat Thyrotoxicosis would we give them thyroid hormone alone?
No, that would end up making the Hyperthyroidism worse