Hyperthyroidism

Question 1

Recall 2 possible causes of hyperthyroidism

Answer 1

1. Grave’s disease

2. Plummer’s disease (nodular goitre)

Question 2

How do the symptoms of Plummer’s and Grave’s differ?

Answer 2

Plummer’s is not AI so there is no exopthalmos/ pretibial myxoedema

Question 3

Recall 11 clinical features of Grave’s disease

Answer 3

Muscle wasting
Weight loss
Tachycardia
Oligomenorrhoea
Tremor
Diarrhoea
Heat intolerance
Goitre
Exopthalmos
Pretibial myxoedema
Lid lag

Question 4

Recall 4 treatment options for hyperthyroidism, discluding surgery

Answer 4

Thionamides
KI
Radioiodine
Beta blockers

Question 5

Give 2 examples of thionamide drugs

Answer 5

Propylthiouracil

Carbimazole

Question 6

Recall the mechnism of action of propylthiouracil

Answer 6

Inhibits TPO, so T4 cannot be converted to T3

Question 7

Describe the pharmacokinetics of carbimazole

Answer 7

Orally active; is a prodrug that is metabolised to its active form, methimazole, metabolised in liver and secreted in urine

Question 8

What is the main clinical use of KI treatment?

Answer 8

Preparation of hyperthyroid patients for surgery

Question 9

Recall the mechanism of action of KI

Answer 9

Inhibits iodination of tyrosine residues and iodination of TG1/2

Question 10

What is the Wolff-Chaikoff effect?

Answer 10

Ingestion of iodine –> reduction in thyroxine
When KI is used to treat hyperthyroidism it inhibits iodination of TG and H2O2 generation, inhibition of thyroid hormone secretion has an autoregulatory effect

Question 11

What is the effect of radioiodine treatment?

Answer 11

It totally switches off the gland, and a replacement must be used from then onwards

Question 12

How does radioiodine work to treat an over-active thyroid?

Answer 12

Radioactive iodine accumulates in colloid of thyroid follicles and destroys thyroid

Question 13

What are beta-blockers used for in the treatment of hyperthyroidism?

Answer 13

Purely symptomatic treatment - used whilst waiting for other drugs to take effect

Question 14

Recall 2 side-effects of thionamides

Answer 14

Agranulocytosis (neutropenia)

Rashes

Question 15

What other name is given to viral thyroiditis?

Answer 15

De Quervain’s Thyroiditis

Question 16

Recall 4 symptoms of viral thyrioditis

Answer 16

1. Dysphagia
2. Initial hyperthyroidism that –> hypothyroidism after 1 month
3. Pyrexia
4. Raised ESR

Question 17

Recall the pathophysiology of viral thyroiditis

Answer 17

Virus attacks thyroid causing pain, thyroid stops producing thyroxine and makes viruses instead. No iodine uptake.

Question 18

Recall the 5 clinical features of a thyroid storm

Answer 18

Hyperpyrexia
Accelerated tachycardia and arrhythmia
Cardiac failure
Delirium
Hepatocellular dysfunction and jaundice