Thyroid hormone drugs for hypothydroidism

Question 1

How do they work?

Answer 1

They are synthetic versions of the hormones

Question 2

What can hypothyroidism cause?

Answer 2

Lethargy
Weight gain
Constipation
Slowing of mental processes

Question 3

What are the side effects of these drugs?

Answer 3

GI upset
Cardiac e.g. palpitations, arrhythmias, angina
Neurological e.g. tremor, restlessness, insomnia
Weight loss

These are associated with dose

Question 4

What are the warnings of this drug?

Answer 4

Precipitate cardiac ischaemia in people with coronary artery disease

Question 5

What are the interactions of this drug class?

Answer 5

Antacids, calcium and iron salts reduce GI absorption of levothyroxine need to separate administration by 4 hours

Enzyme inducer drugs- need an increase in levothyroxine dose

Levothyroxine induced changes in metabolism can increase requirements for glucose-lowering treatments and may enhance effects of warfarin.