Hyperthyroidism Flashcards
what is the role of tsh?
increases activation and production and storage of thyroxine
causes release of active t3 and t4 into circulation
is t3 more active than t4 and what does it do?
controls your body temp and basal metabolic rate
what effect does t3 and t4 have on hypothalamus
negative feedback
what is graves disease?
autoimmune condition
antibodies bind to tsh receptors in thyroid
causes smooth goitre
= hyperthyroidism
what are some symptoms of graves disease
high temp weight loss sweating palpitations and tachycardia diarhoea oligomenorrhoea/amenorrhoea exopthalmos? - diff antibody that stimulates gf other antibodies can cause pretibial myxoedema(hypertrophy)
what is pretibial myxodema
swelling that occurs on shins of patients with graves disease
growth of soft tissue
what would you expect to see in a patient with graves disease
diffuse goitre of moderate size and uniform radioiodine uptake
what is another cause of hyperthroidism
plummers disease
what is plummers disease
not autoimmune
toxic nodular goitre
it is a benign adenoma - hyperfunctioning
no pretibial myxoedema or exopthalmos
effects of thyroxine on sns
thyroxine = sensitised beta adrenoreceptors to ambient levels of adrenaline and noradrenaline whole sns = overactive tachycaridia palpitations tremor lidlag
what is the term given to when hyperthyroid condition worsens?
thyroid storm
50% mortality untreated
start treament immediately
what are the features of thyroid storm
will have 2/more of: hyperpyrexia >41 degress acccelerated tachycardia/arrythmia cardiac failure delirim/psychosis hepatocellular dysfunction - jaundice
treatment options for thyroid storm
surgery - thyroidectomy
radioiodine
drugs -
what are the drugs used in hyperthyroidism
- thionamides : propylthiouracil(ptu) and carbimazole(cbz)
- potassium iodide
- radioiodine
- beta blockers - help symptoms
what do you use the thionamides for?
daily treatment of graves and plummers
what is the mechanism of thionamides
blocks thyroid peroxidase
stops thyroxine synthesis and secretion
what are the side effects of thionamides?
agranulocytosis - reduction of neutrophils - rare and reversible
rashes - uncommon
how do you follow up drig treatment of hyperthyroidism
usually aim to stop anti-thyroid drug treatment after 18 months
review patient periodically
role of beta blockers in thyrotoxicosis
reduce tremor
slow heart rate
when would you used iodide(ki)
preparation of hyperthyroid patients for surgery
for thyroid storm
ki blockes iodide uptake
problems with surgery
risk of voice change
risk of losing parathyroid gland
scars
aesthetics
how do we use radioiodine
swallow capsule containg 370 mbq of isotope
not used in preg and children
need to replace thyroxine after
iodine = expensive. cheaper available for scans
what is viral (de quervains) thyroiditis
virus damages gland and release all stored thyroxine
inflammatory
painful dysphagia
thyroid stops making thyroxine and makes virus
no iodine uptake
become hypothyroid
what is postpartum thyroiditis
similar to viral one but no pain
usually after pregnancy
