Octreotide, an octapeptide, is a long-acting analogue of somatostatin which contains the amino-acid sequence necessary for receptor binding. It inhibits the release of gut hormones from gastroenteropancreatic tumours and hence inhibits their peripheral actions. Up to ninety per cent of patients with hormonal syndromes respond to octreotide with a reduction in symptoms and hormone levels, and it can be life-saving in a VIPoma crisis. It is administered subcutaneously starting at doses as low as 50┬╡g twice daily, increasing to a maximum of 500┬╡g three times daily as effectiveness is progressively reduced.
