Thyroid Tests and Treatment Flashcards
decreased TSH
increased FT4 and/or FT3
Overt hyperthyroidism
decreased TSH
FT4 & FT3 in normal range
Subclinical hyperthyroidism
What additional blood test is carried out if thyroiditis is suspected?
check erythrocyte sedimentation rate
check C-reactive protein
(inflammatory markers)
TSH levels are low in…
Hyperthyroidism
TSH levels are high in…
Hypothyroidism
increased TSH
decreased FT4
Primary Hypothyroidism
increased TSH
FT4 in normal range
Subclinical Hypothyroidism
TSH levels inappropriately low (could be normal)
decreased FT4
Secondary Hypothyroidism
Additional blood tests to carry out if Primary Hypothyroidism is suspected…
full blood count and serum B12 level
assess for pernicious anaemia
glycated haemoglobin (HbA1c)
assess for associated diabetes mellitus
What else do you check if subclinical hypothyroidism is suspected, and why?
serum thyroid peroxidase antibodies
can predict progression to overt hypothyroidism
What are synthetic thyroid hormones used as treatment for? (4)
hypothyroidism
diffuse non-toxic goitre
Hashimoto’s thyroiditis
thyroid carcinoma
What is Hashimoto’s thyroiditis?
lymphadenoid goitre
Synthetic thyroid hormone examples
Levothyroxine sodium (T4, thyroxine sodium) Liothyronine sodium (synthetic T3)
What is used in first line treatment for hypothyroidism?
Levothyroxine sodium
What is used for treatment in severe emergency hypothyroid states?
Liothyronine sodium
Synthetic thyroid hormones may precipitate…
arrhythmias
angina pectoris
cardiac failure
Causes of Hyperthyroidism
Thyrotoxicosis
Diffuse toxic goitre
Toxic nodular goitre
Thyrotoxicosis may manifest itself as..
high metabolic rate
increase in skin temperature and sweating
nervousness, tremor
increased appetite, weight loss
Treatments available for Hyperthyroidism
Radioactive Sodium Iodide
Carbimazole
Propylthiouracil
Iodine/Iodide
Radioactive Sodium Iodide Mechanism of Action
Emits beta and gamma radiation
destruction of thyroid tissue
require subsequent T4 replacement therapy
Which hyperthyroid drugs are Thioureylenes
Carbimazole
Propylthiouracil
Carbimazole Mechanism of Action
decrease output of thyroid hormones
thought to inhibit iodination of thyroglobulin
Propylthiouracil Mechanism of Action
decrease output of thyroid hormones
blocks T4 to T3 conversion in peripheral tissues
Treatment for Thyrotoxic Crisis
IV fluids propanolol hydrochloride hydrocortisone oral iodine solution carbimazole / propylthiouracil
