Thyroid Pharmacology

Question 1

What are the symptoms of hyperthyroidism and thyrotoxicity?
Treatment :
5 treatments

Answer 1

Hyperthyroidism:foot on accelerator = sweaty, warm ,tachycardia ,nervous, shaky , palpitations, increased appetite and decreased weight, manic levels of energy

Treatment:

• Block the thyroid hormone being released = thioureylenes (inhibit thyroid peroxidase)
• beta-blocker (propranolol = non selective beta-blocker)
• Block is replace using carbimazole + Levothyroxine ( synthetic thyroid hormone )
• Radioactive iodine = radiation damages the thyroid follicle cells so you will need life long administration of T4
• Surgery

Question 2

Thioureylenes case study

Answer 2

Pro-drug carbimazole–>methimazole

• Taken orally
• 18-24months

Block the thyroid hormone from being produced!
- Thyroid peroxidase is inhibited so T3,T4 is not made

Side effects :

• rash , nausea
• Rare= Agranulocytosis (marrow suppression, infections and sore throat)
• Pregnancy = can cause goitre, it crosses the placenta so it can cause hypothyroid in the fetus

Question 3

How can propranolol treat thyrotoxic symtpoms

Answer 3

• non selective beta blocker
• Inhibits t4, T3 action on peripheral tissues
• improves palpitations, arrhythmias, tremor etc

Question 4

Outline block and replace treatment of Hyperthyroidism

Answer 4

1-Carbimazole ( blocks all T3,T4) + Levothyroxine (synthetic thyroid hormone ) NEW T3,T4 has to be released

Question 5

What does Radioactive Iodine do ?

Answer 5

• Oral one dose
• Emits short beta radiation damaging thyroid follicle cells
• leads to hypothyroidism = therefore you need to give T4 FOR THE rest of their lives .

Question 6

What is levothyroxine

Answer 6

• Man made Thyroid hormone

Question 7

Hypothyroidism

Answer 7

1- slows down the foot of the accelerator, cold, tired, delayed reflex, weight gain, loss of hair, poor appetite , dry and thick skin

2-Treatment :
- Levothyroxine = T4 50-150 micrograms
Synthetic T4

Question 8

what is amiodarone

Answer 8

Anti arrythmic

- Contains iodine and can cause hyper or hypothyroidism

Question 9

What does Lithium do

Answer 9

• Decreases thyroid function
• Rarely significantly
• Check the TSH for 6-12 months !