Endocrine: Thyroid

Question 1

What can we measure to assess Thyroid function?

Answer 1

• GOLD STANDARD: Thyroid Stimulating Hormone (TSH)
• T4
• T3

Question 2

Normal range of Thyroid Stimulating Hormone (TSH)?

Answer 2

0.3 to 5 milliunits/L per ATI

Question 3

What are some drugs used to treat Hypothyroidism?

Answer 3

• Levothyroxine
• Liothyronine (desiccated thyroid)

Question 4

What are some causes of Hypothyroidism?

Answer 4

• Autoimmune Diseases (most common)
• Hashimoto’s
• Surgically removed thyroid (thyroid cancer)
• Certain Drugs: Lithium, Amiodarone

Question 5

What are some common symptoms of Hypothyroidism?

Answer 5

• Thickened skin
• Hair loss
• Constipation
• Lethargy
• Weight gain
• Bradycardia
• Sleepy all the time
• Anorexia (no appetite)

Question 6

Describe how thyroid drugs work to treat Hypothyroidism.

Answer 6

• Thyroid drugs are given to replace what the thyroid gland cannot produce to achieve normal thyroid levels (euthyroid).
• These drugs are used for the rest of the patient’s life
• Goal is to normalize TSH AND improve patient’s symptoms

Question 7

Hypothyroidism treatment?

Answer 7

• Levothyroxine (GOLD STANDARD)= Synthetic T4 (Levo= 4 letters)
• Liothyronine= Synthetic T3 (Lio= 3 letters)
• Dessicated Animal Thyroid (Guidelines recommend AVOIDING)

Question 8

What is Levothyroxine (T4) used to treat?

Answer 8

• Treat all forms of hypothyroidism
• Myxedema Coma

Question 9

Levothyroxine special note?

Answer 9

• REMEMBER: Some people classify this as a catecholamine (increased alertness)

Question 10

Levothyroxine adverse effects?

Answer 10

Overdose- “Hyperthyroidism”

• Heat intolerance
• Excitement (insomnia)
• Angina / Afib
• Restless
• Tachycardia/Tremor

Question 11

Boxed Warning for Levothyroxine?

Answer 11

Boxed Warning: FDA recommends not to use as treatment for obesity/weight loss

Question 12

Describe Levothyroxine Administration.

Answer 12

• Start with a low dose and increase based on TSH + symptoms
• Check a pulse before giving (hold if >100)
• This drug requires an empty stomach (acidic pH)
• Give first thing in the morning

Question 13

Levothyroxine drug interactions?

Answer 13

• Concern with mixing with other drugs that can change pH of stomach (Antacids- Tums®)
• Do not administer with bile acid sequestrants (cholestyramine) separate by 4 hours

Question 14

Levothyroxine drug profile?

Answer 14

Keep in mind this is a NARROW THERAPEUTIC INDEX drug

Question 15

When is Liothyronine (T3) used?

Answer 15

• Used when someone has an issue converting to T4 to T3 (extremely rare)
• Used when someone is not sufficiently controlled with T4

Question 16

Liothyronine (T3) and Desiccated Animal Thyroid (T4:T3 ratio) adverse effects?

Answer 16

• Heat intolerance
• Excitement (insomnia)
• Angina
• Restless
• Tachycardia/Tremor

Question 17

What is Hyperthyroidism caused by?

Answer 17

• Graves’ disease
• Thyroid storm

Question 18

Hyperthyroidism S/S?

Answer 18

Affects multiple body systems, resulting in an overall increase in metabolism

• Diarrhea
• Increased appetite
• Weight loss
• Muscle weakness
• Altered menstrual flow
• Flushing
• Fatigue
• Palpitations
• Nervousness
• Irritability

Heat intolerance
Excitement (insomnia)
Angina
Restless
Tachycardia/Tremor

Question 19

How is Hyperthyroidism managed?

Answer 19

• Surgery- remove part/all of thyroid
• Pharmacological Drug therapy for rest of life
• Radioactive Iodine to destroy Thyroid

Question 20

What drugs are used to treat Hyperthyroidism?

Answer 20

Main Drugs:

• Methimazole
• Propylthiouracil (PTU)

Extra Drugs:

• Radioactive Iodine (I-131)
• Potassium Iodide

Question 21

What is Methimazole + Propylthiouracil (PTU) used to treat?

Answer 21

• Hyperthyroidism
• Graves Disease
• Thyroid Storm

Question 22

Describe PTU.

Answer 22

PTU= Puts Thyroid Under
- They suppress creation of thyroid hormone

Question 23

Methimazole + PTU adverse effects?

Answer 23

• Liver and Bone Marrow Suppression
• PTU- BOXED WARNING- hepatotoxicity

Question 24

Methimazole + PTU patient education?

Answer 24

Avoid eating foods high in iodine (seafood, soy sauce, tofu, and iodized salt)

Question 25

How should Methimazole + PTU be administered?

Answer 25

• Better tolerated when given with food
• Give at the same time each day to maintain consistent blood levels.
• Never stop these medications abruptly.

Question 26

Describe Thyroid Storm.

Answer 26

Extreme surge of thyroid hormone (T3 +T4).

• Induced by Stress or Infection
• EXTREMELY DANGEROUS
• HEART
• Patients will present with tachycardia/atrial fibrillation, fever, confusion, maybe even organ damage

Question 27

Thyroid Storm treatment?

Answer 27

• Give Propranolol
• Give PTU (or maybe Methimazole)

Question 28

What does Radioactive Iodine do (I-131)?

Answer 28

• Surgery to remove all or part of the thyroid gland
  
  • Lifelong thyroid hormone replacement will be needed.

Question 29

What is Radioactive Iodine (I-131) used to treat?

Answer 29

• Graves Disease
• Thyroid Tumor
• Goiter

Question 30

What is Potassium Iodide (SSKI) used to treat?

Answer 30

• Following radioactive iodine exposure, potassium iodide blocks the uptake of radioactive iodine by the thyroid, reducing the risk of thyroid cancer and thyroid destruction
• Thyroid Storm/Thyrotoxicosis