Week 13 - Hyperthyroidism Pharmacology Flashcards
1
Q
How is hyperthyroidism treated? (3)
A
- Methimazole (tapazole)
- beta adrenergic blocker (propanalol)
- Iodine
2
Q
What is the MOA of Methimazole? (2)
A
- inhibits synthesis of thyroid hormone and PTU also blocks peripheral conversion of T4 to T3
- does not destroy store of thyroid hormone, so may take 3-12 weeks to become euthyroid)
3
Q
Why are beta blockers used for hyperthyroidism?
A
- Symptom relief due to high beta-adrenergic receptor stimulation from thyroid hormones
note we should not use them sometimes bc it masks hypoglycemia
4
Q
Why is iodine used for hyperthyroidism? (2)
A
- short term prior to surgery or in crisis
- rapidly inhibits T3 and T4 synthesis and release, decreases vascularity of thyroid gland
5
Q
Why is radioactive iodine used to treat hyperthyroidism?
A
- Destroys thyroid tissue (cannot have if pregnant)
6
Q
How is surgery used to treat hyperthyroidism? (2)
A
- subtotal thyroidectomy
- removes significant part of thyroid gland
7
Q
What is methimazole used to treat? (3)
A
- Graves’ disease
- adjunct to radiation therapy
- prior to surgery
8
Q
What is the plasma half life of methimazole?
A
6-13 hours (allows for once/da`y dosing)
9
Q
What are the adverse effects of methimazole? (2)
A
- generally well tolerated, but should be avoided by pregnant women
- Most dangerous toxicity is agranulocytosis (will reverse once meds stop)
10
Q
In lecture, what is agranulocytosis? (2)
A
- severe immunodeficiency where no WBC
- sore throat is common
11
Q
How can nutrition therapy treat hyperthyroidism? (3)
A
- High calorie for hunger and prevention of tissue breakdown
- Protein allowance 1-2g/kg of ideal body weight
- avoid caffeine, highly seasoned foods, high fibre foods to decrease abdominal pain
