revision from zero to finals on endocrinology Flashcards
which disease causes pretibial myxoedema?
graves disease- due to TSH autoantibodies
what is the effect of aldosterone on electrolytes?
Aldosterone causes… - - sodium reabsorption
- potassium and hydrogen excretion
- you expect to find hypokalaemia, hypertension and alkalosis.
- serum sodium will be a bit higher than normal
what are the serum renin levels like in primary vs secondary hyperaldosteronism?
primary- there is too little renin because there is too much aldosterone being produced by an adenoma, which will cause negative feedback on renin
secondary- there will be too much serum rein as this is what is causing there to be too much aldosterone
what is tolvaptan?
ADH receptor blocker- used to treat SIADH- when ADH levels are too high
what is desmopressin?
synthetic add- sed to heat diabetes insidipidus, when not enough ADH is being release from the posterior pituitary
a higher dose is needed to treat nephrogenic diabetes insidious in order to overcome the resistance to ADH
what are the side effects of demeclocycline?
(a tetracycline antibiotic with the side effect of blocking ADH)
when to do long vs short synacthen test?
used when testing for adrenal insufficiency
- short test is to check a normal response- which would be the cortisol almost doubling if nothing is wrong
- if there is something wrong you should do the long test
- if still no cortisol is produced- then primary adrenal insufficiency= Addison disease
- if some cortisol is produced its secondary insufficiency and it was the pituitary not producing enough ACTH- - this wold have caused some of the adrenal gland to atrophy- atrophied gland can still respond if there is sufficient stimulation
what is the effect of lithium on thyroid hormones?
inhibits the production of thyroid hormones in the thyroid gland and can cause a goitre and hypothyroidism
what is the effector amioderone on thyroid hormones?
interferes with thyroid hormone production and metabolism, usually causing hypothyroidism but it can also cause thyrotoxicosis. (another term for hyperthyroidism
what tolerance test do you do for acromegaly?
• Oral glucose tolerance test whilst measuring growth hormone (high glucose normally suppresses growth hormone
what is the initial screen for acromegaly?
• Insulin-like Growth Factor 1 (IGF-1) is the initial screening test (raised)
what is pegvisomat used for ?
used for treatment of acromegaly
it is a GH antagonist given subcutaneously and daily
what drugs can be given for acromegaly?
gvisomant (GH antagonist given subcutaneously and daily)
• Somatostatin analogues to block GH release (e.g. ocreotide)
• Dopamine agonists to block GH release (e.g. bromocriptine)
what is an example of a somatostatin analogue?
ocreotide
what is the treatment for phaeochromocytoma?
- Alpha blockers (i.e. phenoxybenzamine)
- Beta blockers once established on alpha blockers- about 3 weeks later- propranolol
what is the risk of propylthiouracil for hyperthyroidism?
- There is a small risk of severe hepatic reactions, including death
what are cautions for someone taking radioactive iodine for hyperthyroidism?
- Must not be pregnant and are not allowed to get pregnant within 6 months
- Must avoid close contact with children and pregnant women for 3 weeks (depending on the dose)
- Limit contact with anyone for several days after receiving the dose
what is the test of choice when investigating bushings syndrome?
dexamethasone supression test giving the synthetic steroid in the night and seeing if there ha been negative feedback and a subsequent suppression of normal circadian peak in the morning
what are the signs of cushings?
- buffalo hump
- moon face
- thin hair
- central adiposity
what type of cushings syndrome does not result in reduction of cortisol after high dose dexamethasone supression?
- ectopic ACTH secreting tumour
what are complications of cashing?
cvd- HTN, IHD
endo- T2DM
musculoskeletal- osteoporosis
infection- they are immune comprimised
what is the test for adrenal insufficiency?
synacthen- synthetic ACTH testing
- cortisol levels should increase after administration
- if they do not this suggests primary adrenal insufficiency as adrenals are not responding to ACTH
what is the point of the long synacthen test?
- to make sure if its primary or secondary adrenal insufficiency
- if it is secondary then the long test will result in some cortisol increase as the ACTH will manage to get some cortisol out of atrophied adrenals
adrenals atrophy in secondary insufficiency due to lack of situation by ACTH
