Thyroid Medications Flashcards
What is the largest endocrine gland?
Thyroid
What 3 hormones are produced from the thyroid?
1) Thyroxine (T4; converts to T3)
2) Triiodothyronine (T3)
3) Calcitonin
What two hormones produced by the thyroid are needed for metabolism?
T4 & T3
What other part of the body plays a role in regulation of thyroid
Hypothalamus that secretes a thyrotropin-releasing hormone (TRH)
What does TRH stimulate?
The pituitary gland to produce a thyroid-stimulating hormone (TSH) that in turn stimulates the thyroid to produce the thyroid hormones
The body requires ____ to make thyroid hormones in the thyroid gland
iodine
Iodine is a component of what 2 thyroid hormones?
T3 & T4 → that regulate metabolism, growth, & development
Define euthyroid
Normal thyroid gland function
Define goiter
Visible enlargement of the thyroid gland
Define Graves Disease
Antibody mediated autoimmune disease resulting in hyperthyroidism
Define Hashimoto’s Thyroiditis
Autoimmune disease often resulting in hypothyroidism
Thyroid hormone functions:
Stimulates ____ ____ & _____ _____ of cells
Metabolic activity; oxygen consumption
Thyroid hormone functions:
Produces ____ & ____
Heat & thermogenesis
Thyroid hormone functions:
Stimulates ______, ____, & ____ metabolism
Carbohydrate, fat & protein metabolism
Thyroid hormone functions:
Increases what 2 things
1) rate of glucose absorption
2) erythropoiesis
Thyroid hormone functions:
Plays a role in regulating ___
Mood
Thyroid hormone functions:
What 3 things do thyroid hormones work with to promote growth?
1) Growth hormone
2) insulin
3) sex steroids
Thyroid hormones are required for what 2 things?
1) normal respiratory response to hypoxia
2) hypercapnia respiratory drive
Thyroid hormones are critical for fetal ____ & ____ development
Fetal neural & skeletal development
What is secretion of T3 & T4 controlled by?
TSH from the anterior pituitary
TSH control rate of thyroid hormone release via a _____ feedback mechanism
Negative
What determines the release of TSH
Levels of thyroid hormones in the blood
What do excess hormones lead to
inhibition of TSH
What do low hormones lead to
Increase production of TSH
How is the hypothalamus connected to TSH?
Hypothalamus releases thyrotropin releasing hormone (TRH) which stimulates the pituitary to release TSH
Normal thyroid levels
TSH (0.4 to 4.5)
What does it mean if thyroid levels are less than 0.4
Hyperthyroidism/ overactive thyroid
What does it mean if thyroid levels are above 4.5
Hypothyroid/ underactive thyroid
Normal range of T4 levels
4-11
Normal range of T3 levels
80-180
list 10 symptoms of HYPOthyroidism
1) fatigue
2) depression
3) dry skin
4) constipation
5) bradycardia
6) altered menstrual cycles
7) weight gain
8) changes in hair
9) cold intolerance
10) cardiac enlargement if prolonged
What is hypothyroidism?
decrease in hormone production
Hypothyroidism can be ____ or ____
A primary problem or autoimmune (Hashimoto’s thyroiditis)
What is known as severe hypothyroidism?
Myxedema
List 2 medications used to treat hypothyroidism
1) levothyroxine
2) Armour thyroid (desiccated)
List 3 medications used to treat hyperthyroidism
1) Methimazole
2) Propylthiouracil (PTU)
3) Iodine solutions
Levothyroxine can also be called _____, _____
Synthroid
Levoxyl
Levothyroxine is a synthetic form of ____
T4
4 things to remember with use of levothyroxine
1) good bioavailability & reliability
2) Half life of 6-7 days
3) highly protein bound
4) should be taken on empty stomach 30 min before breakfast
What is the goal of using levothyroxine
Restore the TSH and T4 back to normal
Side effects of levothyroxine
Usually similar to hyperthyroidism if dose is too high
Desiccated thyroid medication is also known as
Armour thyroid
What does dessicated thyroid come from?
Thyroid extract that comes from animal thyroid glands that have been dried & powdered
Desiccated thyroid contains what 2 hormones
T3 & T4
What does bioavailability look like in desiccated thyroid
variable bioavailability
Side effects of desiccated thyroid Hint: 3
1) change in appetite
2) chest pain
3) diarrhea
Nursing considerations when using hypothyroidism medications Hint: 6
1) doses individualized based on TSH results
2) avoid giving Ca containing meds, antacids, or iron supplements at same time
3) assess HR prior to giving (Consult if tachycardic)
4) it’s a life long med
5) TSH should be checked regularly until dose stabilizes
6) safe in pregnancy
When should TSH levels start being checked after starting a hypothyroid med?
Levels checked 6-8 weeks after starting & after dose changes
-then annually
-may need to check LFTs & WBCs
What is hyperthyroidism?
Increased in circulating T3 & T4 which comes from overactive thyroid or excessive thyroid hormone production
Can be mild or lead to death if not treated
Hyperthyroidism is assoicated with what autoimmune disease?
Graves disease → caused by hyperfunctioning of thyroid gland
Why is it important to evaluate/ monitor patient’s with HYPERthyroidism a little more?
They are at increased risk of thyroid cancer
What is Tepezza used to treat?
thyroid eye diseases
List 10 Sx of hyperthyroidism
1) Anxiety
2) Restlessness
3) Diaphoresis
4) N/V/D
5) Tachycardia (check for A fib)
6) Weight loss
7) Heat intolerance
8) exophthalmos
9) Changes in menstrual cycle
10) Insomnia
What does Tx of hyperthyroidism depend on & what is it directed at?
Dependent on underlying cause
Directed at:
1) decreasing thyroid hyperactivity
2) preventing complications
Tx of hyperthyroidism can be single or combo therapy consisting of? Hint: 3
1) Anti-thyroid agents
2) radioactive iodine
3) surgery
What does Tx of hyperthyroidism often result in?
Recurrent hyperthyroidism or permanent hyperthyroidism
How do thioamides work to TX hyperthyroidism?
1) lower levels by inhibiting formation of thyroid hormones in the cells
2) inhibit conversion of T4 to T3
What two lab tests must be obtained prior to starting thioamides?
CBC & liver profile
How should thioamides be taken?
On an empty stomach 30 minutes before eating
When do we usually see thioamides effectiveness?
Can take several weeks to see effect
What thioamide drug is the drug of choice unless pregnant?
Methimazole
How many times of day is Methimazole administered?
Once a day
What do side effects of Methimazole come from? & what are they?
Thyroid suppression
Less GI side effects
Can cause BM suppression
What thioamide drug converts T4 to T3
Propylthiouracil (PTU)
How should PTU be administered to pregnant women?
Can be used during the 1st trimester of pregnancy then should be stopped
PTU has several drug interactions so its important to monitor what labs?
LFTs → increase risk of liver injury
CBC → leukopenia
List two types of Iodine drugs used to Tx hyperthyroidism
1) Lugol’s solution
2) I-131
Which iodine drug is for short term use?
Lugol’s solution
What does Lugol’s solution inhibit?
Release of T3 & T4
Lugol’s Solution can cause ____. List 4 Sx associated
Ionism
1) metallic taste
2) stomatitis
3) sore throat
4) hypersensitivity
What type of iodine is radioactive?
I-131
What is I-131 typically used for?
Thyroid cancer, Thyrotoxicosis, or special cases
list 3 important points to note when using I-131
1) increase fluid intake
2) contraindicated during pregnancy
3) radiation precautions
What is the adjuvant therapy used for hyperthyroidism?
Beta blockers
List 2 beta blockers used to control Sx of hyperthyroidism
1) Propanolol
2) Atenolol
When would we use beta blockers to Tx hyperthyroidism?
In older adults when HR is > 90 or may have HX of arrhythmias, HTN, or chest pain
What meds are mainly used to control Sx while waiting for meds to take effects?
Beta blockers
