Flashcards in Hyperthyroid Deck (9):
excess thyroid hormone, usually T4 thyroxine. Usually due to glandular hyperfunction.
T3 is tri iodothyronine.
Graves MOST COMMON (Ab activation of TSH R). AI.
toxic goitre or adenoma
metastatic differentiated thyroid CA
TSH secreting pituitary adenoma
-Non hyperthyroid causes-
Exogenous thyroid hormone eg drugs, supplements, meat.
Pregnancy, amiodarone, IFNa.
Weight loss BUT VERY GOOD APPETITE.
Diarrhoea or hyperdefecation
Restless, nervous, emotional, irritable.
Oligomenorrhoea infrequent, possible infertility
Atypical CP and SOB on exertion.
Rare- psychosis, chorea, panic, itch, alopecia, urticaria.
Fast irregular pulse
Systolic HTN with increased PP.
Warm moist skin
Lid lag and retraction
Possible goitre, nodules, bruit.
Graves signs- exophthalmos (adipose accumulation), clubbing, goitre.
BB to alleviate SNS manifestations eg palpitations, tremor, anxiety.
Thionamides inhibit thyroid hormone biosynthesis by competitive inhibition of iodine organification and iodotyrosine coupling.
Carbimazole inhibits peroxidase incorporation of iodine into TG.
Saturated solution of K iodide or lugols solution inhibit thyroid hormone synthesis and release ST.
For thyroid storm- antipyretics, BB, thionamides, iodinated contrast agents, GCs.
Thyorotoxicosis- rapid irregular HR, high temp, vomiting, diarrhoea, agitation.
Tx with antithyroid drugs and BBs.
TSH levels low due to negative feedback
high circulating T3 and 4.
Screen for serum TSH R Abs.
Graves- normocytic anaemia, neutropenia.
Can get high ESR, Ca, LFT.
Test eye function.
T3 more potent than T4 but shorter t1/2.
Much more T4 is produced than T3 but peripheral conversion.
99% bound to eg TBG in plasma, T4 with higher affinity.
T4 used to treat hypothyroid as longer t1/2