Octreotide (brand name Sandostatin,[1] Novartis Pharmaceuticals) is an octapeptide that mimics natural somatostatin pharmacologically, though it is a more potent inhibitor of growthhormone, glucagon, and insulin than the natural hormone. t was first synthesi!ed in 1"#" by the chemist $ilfried %auer.Contents 1 &edical uses o 1.1 'umorso 1.( %leeding esophageal variceso 1.) *adiolabelling ( +ontraindications ) ,dverse effects - nteractions . Pharmacological effects / Pharmaco0inetics # *esearch 1 2ee also " *eferencesMedical usesTumors3ctreotide is used for the treatment of growth hormone producing tumors (acromegaly and gigantism), pituitary tumors that secrete thyroid stimulating hormone (thyrotropinoma), diarrhea and flushing episodes associated with carcinoid syndrome, and diarrhea in people with vasoactive intestinal peptide4secreting tumors (5Pomas).Bleeding esophageal varices3ctreotide is often given as an infusion for management of acute haemorrhage from esophageal varices in liver cirrhosis on the basis that it reduces portal venous pressure, though current evidence suggests that this effect is transient and does not improve survival.[(]Radiolabelling6urther information7 3ctreotide scan3ctreotide is used in nuclear medicine imaging by labelling with indium4111 (3ctreoscan) to noninvasively image neuroendocrine and other tumours e8pressing somatostatin receptors.[)] &ore recently, it has been radiolabelled with carbon411 [-] as well as gallium4/1, enabling imaging with positron emission tomography (P9'), which provides higher resolution and sensitivity.3ctreotide can also be labelled with a variety of radionuclides, such as yttrium4": or lutetium41##, to enable peptide receptor radionuclide therapy (P**') for the treatment of unresectable neuroendocrine tumours.Contraindications3ctreotide has not been ade;uately studied for the treatment of children, pregnant and lactating women. 'he drug is given to these groups of patients only if a ris04benefit analysis is positive.[.][/]Adverse effects'he most fre;uent adverse effects (more than 1:< of patients) are headache, hypothyroidism,cardiac conduction changes, gastrointestinal reactions (including cramps, nausea=vomiting and diarrhoea or constipation), gallstones, reduction of insulin release, hyperglycemia [#] or hypoglycemia, and (usually transient) in>ection site reactions. 2low heart rate, s0in reactions such as pruritus, hyperbilirubinemia, hypothyroidism, di!!iness and dyspnoea are also fairly common (more than 1ured by ongoing treatment for acute lymphoblastic leu0emia (,CC) or surgery or radiation to treat posterior cranial fossa tumors.[1.] $ith the 5&B disabled and no longer responding to peripheral energy balance signals, D9fferent sympathetic activity drops, resulting in malaise and reduced energy e8penditure, and vagal activity increases, resulting in increased insulin secretion and adipogenesis.D[11] D5&B dysfunction promotes e8cessive caloric inta0e and decreased caloric e8penditure, leading to continuous and unrelenting weight gain. ,ttempts at caloric restriction or pharmacotherapy with adrenergic or serotonergic agents have previously met with little or only brief success in treating this syndrome.D[1.] n this conte8t, octreotide suppresses the e8cessive release of insulin and may increase its action, thereby inhibiting e8cessive adipose storage. n a small clinical trial in eighteen pediatric patients with intractable weight gain following therapy for ,CC or brain tumors and other evidence of hypothalamic dysfunction, octreotide reduced body mass inde8 (%&) and insulin response during glucose tolerance test, while increasing parent4reported physical activity and ;uality of life (?oC) relative to placebo.[1.] n a separate placebo4controlled trial of obese adults without 0nown hypothalamic lesions, obese patients who received long4acting octreotide lost weight and reduced their %& compared to patients receiving placeboA post hoc analysis suggested greater effects in patients receiving the higher dose of the drug, and among D+aucasian patients having insulin secretion greater than the median of the cohort.D D'here were no statistically significant changes in ?oC scores, body fat, leptin concentration, %ec0 Eepression nventory, or macronutrient inta0eD, although patients ta0ing octreotide had higher blood glucose after a glucose tolerance test than those receiving placebo.[1"]3ctreotide has also been investigated for patients with pain from chronic pancreatitis.[(:]t has been used in the treatment of malignant bowel obstruction.[(1]3ctreotide may be used in con>unction with midodrine to partially reverse peripheral vasodilation in the hepatorenal syndrome. %y increasing systemic vascular resistance, these drugs reduce shunting and improve renal perfusion, prolonging survival until definitive treatment with liver transplant.[((] 2imilarly, octreotide can be used to treat refractory chronic hypotension.[()]$hile successful treatment has been demonstrated in case reports,[(-][(.] larger studies have failed to demonstrate efficacy in treating chylothora8.[(/], small study has shown that octreotide may be effective in the treatment of idiopathic intracranial hypertension.[(#][(1]