Hypothyroidism

Question 1

Is hypothyroidism more common in males or females?

Answer 1

5-10 times more common in females than males.

Question 2

What is the most common cause of Primary Hypothyroidism?

Answer 2

Hashimotos thyroiditis

Question 3

Other causes of Primary Hypothyroidism

Answer 3

Subacute thyroiditis (de Quervain’s)

Riedel thyroiditis

Post-thyroidectomy or radioiodine treatment

Dietary iodine deficiency

Question 4

Drugs which can cause hypothyroidism

Answer 4

lithium
amiodarone
anti-thyroid drugs (e.g. carbimazole)

Question 5

What causes secondary hypothyroidism

Answer 5

pituitary failure

Question 6

What other conditions are associated with hypothyroidism?

Answer 6

Down’s syndrome
Turner’s syndrome
coeliac disease

Question 7

Symptoms of hypothyroidism

Answer 7

Weight gain
Lethargy
Cold intolerance
Dry skin + dry coarse hair
Non-pitting oedema (e.g. hands, face)
Constipation
Menorrhagia
Reduced deep tendon reflexes
Carpal tunnel syndrome

Question 8

What is an accetpable starting dose of levothyroxine?

Answer 8

50100mcg daily

If elderly or IHD
- 25mcg daily

Question 9

How soon after changing the dose of levothyroxine therapy should thyroid function be checked?

Answer 9

8-12 weeks

Question 10

By how much should the dose of levothyroxine therapy be increased during pregnancy?

Answer 10

by at least 25-50 micrograms

Question 11

Side effects of levothyroxine

Answer 11

• hyperthyroidism (over treatment)
• reduced bone mineral density
• worsening of angina
• atrial fibrillation

Question 12

What drugs interact with levothyroxine and how can this be avoided?

Answer 12

iron, calcium carbonate
- cause reduced levothyroxine absoprtion

=> take 4 hours apart