EN5 Flashcards
what is graves’ disease
it is an autoimmune disease when antibodies bind to and stimulate the TSH receptor in the thyroid ==> cause smoothly enlarged goitre ==> high production of T4 and T3
list the clinical features of graves’ disease
increased appetite with weight loss tremour breathlessness sweating tachycardia palpitation heat intolerance diarrhoea lid lag
give 3 features of graves
- hyperthyroidism
- muscle enlargement behind the eyeball
- swelling of sheen ==> pretibial myxoedema
what is the difference between plummer’s disease and graves’ disease
plummer has hot nodule whereas graves’ has overall enlargement
plummer is not autoimmune, its caused by benign adenoma
plummer has no pretibial myxoedema or exophthalmos
why does hyperthyroidism cause lid lag
because thyroxine makes beta adrenoreceptor more sensitive ==> adrenaline has a bigger impact on sympathetic control of the eye lid
what is thyroid storm
its medical emergency
it is a very high level of T4 which could lead to death
list two examples of thionamides
PTU
CBZ
what are the drugs used to treat hyperthyroidism
thionamides
KI
radioiodine
beta-blockers
what is the mechanism of thionamides. What are the side effects?
inhibit thyroid peroxidase hence T4,3 production
some also suppress antibody production
side effects: agranulocytosis and rahses
what does beta blocker do in thyrotoxicosis?
reduce symptoms
e.g propranolol (non-selective)
or cardioselective beta blocker
when do doctors inject KI
- preparation for thyroidectomy
2. to reduce symptoms in severe thyrotoxic crisis e.g thyroid storm
what does kI do
inhibit iodination of TG
inhibit H2O2 generation and thyroperoxidase
what does radioiodine do
accumulate in colloid cell and give off beta particles ==> eventually kill follicular cells
