Acromegaly Flashcards
what is the pathophysiology of acromegaly
too much GH secretion
what are the visible signs associated with acromegaly
giant(if in children before epiphyseal fusion), thickened skin, large jaw, sweaty, large hands, snoring/sleep apnoea
what are the sign and symptoms associated with acromegaly that aren’t visible
hypertension, cardiac failure, headaches(vascular), diabetes mellitus, local pituitary effects(eg visual fields), early CV risk, colon polyps/cancer
what diagnostic tests are used for acromegaly
IGF1 and GTT suppression test(give glucose and check GH every 30mins)
what are the normal and acromegaly results of GTT suppression test
normal = GH suppresses to <0.4ug/l after glucose acromegaly = GH unchanged/no suppression, or paradoxical rise
what other tests can be done when investigating acromegaly
visual fields, CT/MRI of pituitary, pituitary function tests
what non-pharmacological treatment can be used for acromegaly
pituitary surgery, 90% cure if microadenoma, 50% if macroadenoma
radiotherapy
what types of drugs can be used to treat acromegaly
somastatin analogues, dopamine agonists and GH antagonists
describe the use of somastatin analogues in treating acromegaly
reduce GH in most, tumour shrinkage(30-50% size decrease), can use pre-op
describe the use of dopamine agonists in treating acromegaly
works in around 10-15% patients, better when co-secreting prolactin(some pituitary tumours secrete both GH and prolactin)
what are some of the possible side effects of somastatin analogues
local stinging, flatulence, diarrhoea, abdo pains, gallstones
describe the use of GH antagonists in treating acromegaly
last line treatment, binds to GH receptor blocking activity, 85% response rate, doesn’t decrease tumour size, IGF-1 decreases but GH conc. may increase
give an example of a somastatin analogue
Sandostatin LAR, IM injection, 10-30mg
give an example of a dopamine agonist
Cabergoline, up to 3g weekly
give an example of a GH antagonist
Pegvisomant, SC injection, 10-30mg daily
