Thyroid Disorders

Question 1

What is the most common cause of hyperthyroidism?

Answer 1

Autoimmune - Graves (IgG to TSH receptor)
Toxic multinodular goitre
Toxic adenoma
Ectopic thyroid tissue (due to follicular cancer or ovarian teratoma)
Exogenous eg. Levothyroxine, amiodarone, Lithium
Subacute De Quervains thyroiditis (post viral painful goitre - treat w/ NSAIDS )
Post partum

Question 2

How is Hyperthyroidism treated?

Answer 2

Propranolol 10-40mg TD/QID
Carbimazole 15-40mg OD
Can be given in combination with low dose levothyroxine 50-150mcg
(to reduce risk of iatrogenic hypothyroidism)

Question 3

Can carbimazole be prescribed in GP?

Answer 3

NO - must be prescribed by a specialist hence have to refer hyperthyroid patients

Question 4

What dangerous side effects can Carbimazole induce?

Answer 4

Neutropenia and Agranulocytosis - pt must report any sign of infection and stop drug immediately (especially sore throat)
Acute pancreatitis

Question 5

What TFT changes do you look for in thyroid cancer?

Answer 5

Often none

Question 6

What causes a thyroid storm?

Answer 6

Tends to be in people with undiagnosed/poorly controlled hyperthyroidism
Infection can also cause it

TS is severe life threatening Hyperthyroidism

Question 7

How is hypothyroidism treated?

Answer 7

Levothyroxine (initially 50mcg OD - titrate up 25-50mcg every 3-4wks) 100-200mcg maintenance dose

If >50yrs - initially 25mcg + adjust according to response

Question 8

What are the most common causes of hypothyroidism?

Answer 8

Primary atrophic hyperthyroidism
Hashimotos
Post thyroidectomy or radioiodine therapy
Iatrogenic - Amiodarone, lithium, Carbimazole
Iodine deficiency (world wide most common cause but not in UK)
Subacute - temp hypo after hyper phase