Bivalent hapten-bearing peptides designed for iodine-131 pretargeted radioimmunotherapy

BACKGROUND: Few studies have compared vasoactive drugs with endoscopic sclerotherapy in the control of acute variceal haemorrhage. Octreotide is widely used for this purpose, but its value remains undetermined. AIMS: To compare octreotide with endoscopic sclerotherapy for acute variceal haemorrhage. PATIENTS: Consecutive patients with acute variceal haemorrhage. METHODS: Patients were randomised at endoscopy to receive either a 48 hour intravenous infusion of 50 pg/h octreotide (n = 73), or emergency sclerotherapy (n = 77). RESULTS: Overall control of bleeding and mortality was not significantly different between octreotide (85%, 62 patients) and sclerotherapy (82%, 63 patients) over the 48 hour trial period (relative risk of rebleeding 0.83; 95% confidence interval (CI) 0.38 to 1.82), irrespective of Child's grading or active bleeding at endoscopy. One major complication was observed in the sclerotherapy group (aspiration) and two in the octreotide group (pulmonary oedema, severe paralytic ileus). During 60 days of follow up there was an overall trend towards an increased mortality in the octreotide group which was not statistically significant (relative risk of dying at 60 days 1.91, 95% CI 0.97 to 3.78, p = 0.06). CONCLUSIONS: The results of this study indicate that intravenous octreotide is as effective as injection sclerotherapy in the control of acute variceal bleeding, but further controlled trials are necessary to evaluate the safety of this treatment.     

Effect of octreotide on systemic, central, and splanchnic haemodynamics in cirrhosis

BACKGROUND/AIMS: Cirrhosis with portal hypertension is associated with changes in the splanchnic and systemic haemodynamics, and subsequent complications, such as bleeding from oesophageal varices, have led to the introduction of long-acting somatostatin analogues in the treatment of portal hypertension. However, reports on the splanchnic and systemic effects of octreotide are contradictory and therefore the aim of the present study was to assess the effects of continuous infusion of octreotide on central and systemic haemodynamics, portal pressures, and hepatic blood flow. METHODS: Thirteen patients with cirrhosis underwent liver vein catheterisation. Portal and arterial blood pressures were determined at baseline and 10, 30, and 50 min after a bolus injection of octreotide 100 micrograms, followed by continuous infusion of octreotide 100 micrograms/ h for 1 h. Hepatic blood flow, cardiac output, central and arterial blood volume, and central circulation time were determined at baseline and 50 min after the start of the octreotide infusion. RESULTS: The mean arterial blood pressure increased during the first 10 min (p < 0.0005), but returned to baseline after 50 min. The central and arterial blood volume (-16%, p < 0.005) and the central circulation time (-8%, p < 0.05) were significantly decreased after 50 min, whereas the cardiac output did not change significantly. The hepatic venous pressure gradient and the hepatic blood flow did not change significantly at any time after infusion of octreotide. CONCLUSIONS: Octreotide does not affect the portal pressure or hepatic blood flow, whereas it may further contract the central blood volume and thereby exert a potentially harmful effect on central hypovolaemia in patients with cirrhosis. However, these early effects do not exclude the possibility that administration of longacting somatostatin analogues over a longer period may have a beneficial effect.     

Effects of arginine, growth hormone-releasing hormone (GHRH) and neostigmine administered singly or in paired combinations on growth hormone (GH) release in pigs

OBJECTIVE: A multicentre study was undertaken to determine the value of somatostatin receptor (sst) scintigraphy in predicting hormonal and visual responses to octreotide treatment in GH-secreting and non-functioning pituitary adenomas. SUBJECTS AND METHODS: Somatostatin receptor scintigraphy was performed in 48 patients (19 acromegaly, 29 non-functioning pituitary adenomas with ophthalmological defects). Results were expressed as an uptake index of the pituitary area. A threshold for positivity was determined in 23 subjects considered as controls. Thirty-five patients were treated for 1 month with octreotide (300 micrograms daily). The therapeutic response was assessed on GH and IGF-I suppression or evolution of the ophthalmological defects. The relationships between the somatostatin receptor scintigraphy result, the therapeutic effect of octreotide and in vitro studies performed in 12 tumours were studied. RESULTS: From the results of control subjects the uptake index threshold for positivity was 2. In patients, somatostatin receptor scintigraphy was positive in 64% and there was no relationship between uptake index and tumour size. In GH tumours, somatostatin receptor scintigraphy was positive in 68%; uptake index was related to octreotide-induced GH and IGF I suppression. The positive predictive value was 100% and the negative predictive value was 50%. In vitro studies showed detectable binding sites for somatostatin with sst2 and sst5 expression in the 4 GH tumours studied although somatostatin receptor scintigraphy was negative in 2 cases. In non-functioning pituitary adenomas somatostatin receptor scintigraphy was positive in 62%. Based on visual effects, the positive predictive value was 61% and the negative predictive value was 100%. A wide distribution of somatostatin binding sites was found in 8 non-functioning pituitary adenomas with expression of sst2 only. CONCLUSION: In the conditions of the study, in patients with acromegaly, positive somatostatin receptor scintigraphy predicts a hormonal response but the value of somatostatin receptor scintigraphy is limited by its low negative predictive value. In patients with non-functioning pituitary adenomas, negative somatostatin receptor scintigraphy predicts that there will be no visual improvement during octreotide treatment.     

Randomised trial of octreotide for long term management of cirrhosis after variceal haemorrhage

OBJECTIVE: To assess the efficacy of long term octreotide as adjuvant treatment to programmed endoscopic sclerotherapy after acute variceal haemorrhage in cirrhotic portal hypertension. DESIGN: Randomised clinical trial. SETTING: University hospital. SUBJECTS: 32 patients with cirrhotic portal hypertension. INTERVENTIONS: Programmed injection sclerotherapy with subcutaneous octreotide 50 micrograms twice daily for 6 months, or programmed injection sclerotherapy alone. MAIN OUTCOME MEASURES: Episodes of recurrent variceal bleeding and survival. RESULTS: Significantly fewer patients receiving combined octreotide and sclerotherapy had episodes of recurrent variceal bleeding compared with patients given sclerotherapy alone (1/16 v 7/16; P = 0.037, Fisher's exact test), and their survival was significantly improved (P < 0.02, log rank test); this improvement was maintained for 12 months after the end of the study. Combined treatment also resulted in a sustained decrease in portal pressure (median decrease -6.0 mm Hg, interquartile range -10 to -4.75 mm Hg, P = 0.0002) compared with sclerotherapy alone (median increase 1.5 mm Hg, interquartile range 0.25 to 3.25 mm Hg), as well as a significant improvement in liver function as assessed by plasma concentrations of bilirubin, albumin, and alanine aminotransferase and by hepatocyte metabolism of aminopyrine labelled with carbon-14. CONCLUSION: Long term octreotide may be a valuable adjuvant to endoscopic sclerotherapy for acute variceal haemorrhage in cirrhotic portal hypertension.     

Effects of ligand priming and multiple-dose injection on tissue uptake of 111In-pentetreotide in rats

In patients undergoing somatostatin receptor scintigraphy, treatment with octreotide (Sandostatin) is usually discontinued 24-48 h before and after injection with the radioligand 111In-pentetreotide ([111In-DTPA(O)]octreotide) (Octreoscan) because octreotide competes with radioligand for the same receptors. However, D?rr et al. and Soresi et al. reported improved visualization of carcinoid and small cell lung cancer lesions, respectively, during continued octreotide treatment. We found that intravenous administration of unlabeled octreotide to rats inhibited the binding of an optimal dose (0.5 microg) of 111In-pentetreotide to somatostatin receptors in pancreas and adrenals in a mass- and time-dependent way. Pretreatment with unlabeled octreotide never increased receptor binding of 111In-pentetreotide. Administration of 100 microg of octreotide decreased receptor-bound radioactivity if given simultaneously with or 10 or 20 min after injection of the radioligand, but had no effect if given 30 min after the radioligand. These findings indicate rapid processing of receptor-bound octreotide and suggest that octreotide treatment of patients undergoing 111In-pentetreotide scintigraphy may be reinitiated as soon as 1 h after radioligand administration.     

Effects of octreotide on biliary lipid composition and occurrence of cholesterol crystals in patients with acromegaly. A prospective study

Treatment with the somatostatin analog octreotide is associated with increased gallstone formation. The mechanism of formation of these stones is unclear. The purpose of this study was to examine the effect of a three-month treatment with octreotide on biliary lipid composition and the occurrence of cholesterol crystals in patients with acromegaly. Thirteen patients with active acromegaly, aged 24-76 years, received octreotide (100 micrograms three times daily) for three months. Fasting gallbladder bile was obtained during upper gastrointestinal endoscopy after ceruletide stimulation. Bile was studied before and at the end of the treatment period (N = 7), only before (N = 4), or only at the end of treatment (N = 2). Before treatment, all bile samples but one were supersaturated with cholesterol. However, none contained cholesterol crystals on microscopic examination. At the end of the treatment period, all but two samples were supersaturated with cholesterol. Three of nine samples contained cholesterol crystals, a proportion significantly higher than before treatment. The relative proportions of bile acids, cholesterol, and phospholipids, and the mean cholesterol saturation index were not different before and during treatment. Follow-up ultrasonography showed the occurrence of gallstones in four patients, including the three patients who had cholesterol crystals. We conclude that: (1) fasting gallbladder bile of patients with acromegaly is frequently supersaturated with cholesterol; (2) treatment with octreotide does not increase cholesterol saturation index, but may induce the occurrence of cholesterol crystals. The data are consistent with the view that gallstones induced by octreotide are cholesterol stones and suggest that the drug may impair gallbladder motility and/or decrease cholesterol nucleation time.     

A prospective randomized trial comparing somatostatin and sclerotherapy in the treatment of acute variceal bleeding

Somatostatin and endoscopic sclerotherapy are widely used in the treatment of acute variceal bleeding. Although objective evidence does exist about the advantages of either treatment, data comparing both procedures are scarce. In order to compare the effectiveness and safety of somatostatin and sclerotherapy in the treatment of acute variceal bleeding, 70 consecutive cirrhotic patients suffering from esophageal variceal hemorrhage and meeting the inclusion criteria were randomly assigned to treatment with somatostatin (35 patients) or sclerotherapy (35 patients). No differences in age, sex, alcohol intake, etiology of cirrhosis and severity of liver failure were found between groups. Failure of treatment (defined as persistence of bleeding despite therapy or subsequent rebleeding within the 48-hr trial period) occurred in seven patients (20%) in the somatostatin group and in six (17.1%) in the sclerotherapy group (NS). Early rebleeding occurred in seven of 28 patients (25%) in the somatostatin group and in five of 29 (17.2%) in the sclerotherapy group (NS). Mortality within the first 6 wk was no different between both groups: 10 (28.5%) and eight (22.8%) in the somatostatin and sclerotherapy groups, respectively. Sclerotherapy, but not somatostatin, was associated with major complications in five cases (14.2%) (p = 0.026), two of which resulted in patient's death. These results suggest that somatostatin is safer, and as effective as sclerotherapy, in controlling acute variceal bleeding until an elective treatment can be established.     

What makes alcohol-dependent individuals early in abstinence crave for alcohol: exposure to the drink, images of drinking, or remembrance of drinks past?

It has been reported that injection of somatostatin into the brain-stem will lead to apnoea in animals. The aim of this study was to determine whether peripheral administration of octreotide, an analogue of somatostatin, could influence the control of breathing. We measured the tidal volume, respiratory rate and ventilatory response to CO2, before and after the intravenous injection of two dose levels of octreotide (0.1 mg and 0.5 mg) or saline in four conscious adult dogs. Injection of octreotide altered the breathing pattern with a mean decrease in the respiratory frequency of 23% (p<0.05) and an increase in the tidal volume by 16% (p<0.05), resulting in no net change in ventilation. The normal value of the ventilatory response to CO2 ranged between 1.0-3.2 L x min(-1) x mmHg(-1), with a minor variance within each dog but a significant difference amongst the four dogs (p<0.05). No significant change in the ventilatory response to CO2 was observed after octreotide. We conclude that intravenous octreotide alters the pattern of breathing but preserves minute ventilation; peripheral administration of octreotide does not influence the ventilatory response to CO2.     

Coagulation studies and platelet function after somatostatin infusion

The effect of short- and long-term somatostatin (GIF) administration on haemostatic function in man was investigated. The dosage programme applied in this study was 250 mug GIF as a bolus injection and 250 mug GIF/h by way of infusion. In five healthy volunteers a short-term (3h) treatment resulted in a statistically significant drop of platelet count and impairment of platelet aggregation at the end of infusion. However, these changes were within the physiologically normal range and disappeared after two hours on all subjects. Other parameters such as bleeding time, thromboplastin and partial thromboplastin time, fibrinogen, fibrin/fibrinogen split products, plasma factor XIII, ethanol gelation test were not affected. In two patients with gastric haemorrhage and persistent amylasaemia a 67 or 120-h treatment induced no remarkable haemostatic defect. By contrast, peptic ulcer bleeding in one patient stopped 60 min after starting the GIF infusion. These studies indicated that somatostatin administration in man at the dosage programme used neither results in clinical evidence indicating bleeding tendency nor does it influence laboratory parameters in an apparent way.     

In vivo responsiveness of morphological variants of growth hormone-producing pituitary adenomas to octreotide

The somatostatin analog, octreotide, is an inhibitor of growth hormone (GH) secretion that has been used to treat patients with GH-producing pituitary tumors. In this study we investigated the in vivo responsiveness to treatment with this analog in patients harboring different morphological types of GH-producing pituitary adenomas. Both GH and insulin-like growth factor I (IGF-I) plasma levels in 30 patients treated with octreotide (300 micrograms/day) for 4 months preoperatively were compared with those from 30 patients who did not receive treatment preoperatively. Tissue samples were studied using ultrastructural and immunohistochemical techniques. Amongst patients harboring densely granulated (DG) adenomas, mean GH levels were reduced to 32 +/- 9% by octreotide, to 30 +/- 7% by surgery and to 26 +/- 9% of baseline by both interventions. Surgery was equally as effective in lowering GH levels in patients with sparsely granulated (SG) adenomas as it was in those with DG adenomas; in patients with SG adenomas, GH levels were reduced by surgery alone to 37 +/- 16% and to 24 +/- 15% when performed following octreotide pretreatment. In contrast, treatment with octreotide alone in patients harbouring SG adenomas reduced GH levels to only 70 +/- 13% of baseline (p < 0.02 compared to surgery alone, or surgery and octreotide). We conclude that the GH inhibitory effects of octreotide are significantly better in patients harboring DG somatotroph adenomas compared with those harboring SG adenomas.     

Helicobacter pylori risk associated with sibship size and family history of gastric diseases in Japanese adults

BACKGROUND: Data on whether long-acting somatostatin analogue octreotide causes or prevents pancreatic injury following endoscopic retrograde cholangiopancreatography (ERCP) are controversial. AIM: This multicentre, prospective trial studied the effect of octreotide on pancreatic injury in a large unselected group of patients after ERCP and endoscopic sphincterotomy. METHODS: The study was carried out in a prospective random manner on 2102 patients in 11 endoscopic centres. Patients in the study received 0.1 mg octreotide acetate and those in the control group received isotonic sodium chloride, subcutaneously before and 45 min after ERCP. Pancreatic injury was assessed by clinical symptoms such as pain, fever and abdominal tenderness. Serum amylase and blood sugar were determined prior to, and 6 and 24 h after the endoscopic procedure. RESULTS: Data from 599 patients in the study group and 600 in the control group were included in the final evaluation. When all the patients were considered, octreotide did not induce pancreatic injury as assessed by clinical symptoms, and diminished the increase of serum amylase levels following ERCP. However, when subgroups of patients were studied, the frequency of increased amylase levels decreased significantly in patients with chronic obstructive pancreatitis and in patients who underwent endoscopic sphincterotomy (P < 0.01). The peak serum glucose level was higher in the treated group when compared to the controls. CONCLUSION: The prophylactic use of long-acting somatostatin does not alter the frequency of post-ERCP pancreatic injury, but it may diminish the rate of increased serum amylase levels in patients with chronic obstructive pancreatitis and also in those with an endoscopic sphincterotomy.     

Dermatotoxicity of agricultural chemicals in the dorsal skin of hairless dogs

BACKGROUND: Standard treatment of inoperable hepatocellular carcinoma has not been established. Somatostatin has been shown to possess antimitotic activity against a variety of non-endocrine tumours. AIMS: To assess the presence of somatostatin receptors in human liver and to treat advanced hepatocellular carcinoma with the somatostatin analogue, octreotide. METHODS: Somatostatin receptors were measured in liver tissue homogenates from patients with acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Fifty eight patients with advanced hepatocellular carcinoma were randomised to receive either subcutaneous octreotide 250 micrograms twice daily, or no treatment. Groups were comparable with respect to age, sex, Okuda classification, presence of cirrhosis, and liver biochemistry and virology. RESULTS: Various amounts of somatostatin receptors were identified in liver tissue of all patients including those with hepatocellular carcinoma. Treated patients had an increased median survival (13 months versus four months, p = 0.002, log rank test) and an increased cumulative survival rate at six and 12 months (75% versus 37%, and 56% versus 13% respectively). Octreotide administration significantly reduced alpha fetoprotein levels at six months. When a multivariable Cox's proportional hazards model was fitted, variables associated with increased survival were: treatment administration, absence of cirrhosis, increased serum albumin, and small tumours. Treated patients clearly had a lower hazard (0.383) in the multivariate analysis. CONCLUSIONS: Octreotide administration significantly improves survival and is a valuable alternative in the treatment of inoperable hepatocellular carcinoma.     

Terlipressin (glypressin) versus somatostatin in the treatment of bleeding esophageal varices--final report of a placebo-controlled, double-blind study

One hundred and six episodes of bleeding from esophageal or gastric varices in 72 patients with cirrhosis of the liver were randomized to treatment either with intravenous terlipressin 2 mg initially and 1 mg every four hours for 24 hours together with bolus injection and continuous infusion of placebo, or with somatostatin 250 micrograms as a bolus and continuous infusion of 250 micrograms/h somatostatin for 24 hours and placebo injections. Standard treatment with transfusions, fluid and electrolyte correction, and lactulose was administered in both groups. In the terlipressin group, 48 out of 53 bleeding episodes (91%) and in the somatostatin group 43 out of 53 bleeds (81%) were initially stopped by the vasoactive drugs. Four of the five bleeds not arrested by terlipressin, and nine of the ten bleeds not arrested by somatostatin, were stopped by balloon tamponade. In one patient in each group variceal bleeding could not be stopped initially, and both patients died. The failure rate of the vasoactive treatment alone, including rebleeds within the study period, was 17% in the terlipressin, and 28% in the somatostatin, group. The initial hemostasis, including balloon tamponade, were 98%, and the definitive bleeding control rates were 89% in both groups. The hospital mortality rate was 21% (11/53) in the terlipressin, and 21% (11/53) in the somatostatin, group. Blood transfusions and duration of bleeding did not differ significantly. The study indicates that a large proportion of bleeds from esophageal and fundic varices can be stopped initially (86%) and definitively controlled (77%) by vasoactive drugs alone.     

Octreotide for treatment of postoperative alimentary tract fistulas

Eighteen patients with postoperative fistulas of the gastrointestinal tract were treated with the somatostatin analog octreotide between November 1989 and November 1992. Fourteen patients had enterocutaneous fistulas: seven from the duodenum and seven from the ileum. Another three patients had pancreatic fistulas, and one patient had a biliary fistula. Within 24 hours of octreotide treatment, a mean reduction of 52% in the intestinal fistulas' output, 40% in the pancreatic fistulas, and 30% in the biliary fistula was noted. In the intestinal fistulas group the closure rate was 72% after a mean of 11 days. Early closure (mean 6 days) was achieved in all three pancreatic fistulas. In the patient with the biliary fistula a 30% reduction was observed twice following the administration of octreotide, and an increase occurred when it was withheld. The reduction rate of the secretions in high-output intestinal fistulas (> 500 ml/day) was higher than in the low-output fistulas (63 +/- 8% versus 39 +/- 4%, p < 0.05). Fistula output and the initial response to octreotide treatment had no value in predicting spontaneous healing. In conclusion, octreotide is a valuable tool for the conservative treatment of fistulas of the digestive tract. It is especially valuable for management of high-output enteric fistulas and pancreatic fistulas.     

Prevalence of symptoms related to asthma in Guadalajara

PURPOSE: We studied the effects of octreotide and ursodiol on the gallbladders of patients with acromegaly. METHODS: We performed gallbladder sonography in patients with acromegaly at various intervals during treatment. Group I (18 patients) was treated with subcutaneous injections of the somatostatin analogue octreotide. Group II (10 patients) was treated with ursodiol while receiving octreotide therapy. RESULTS: Seventy-eight percent of patients receiving octreotide developed gallbladder abnormalities: sludge in 72% (13/18) and calculi in 39% (7/18). Ursodiol reversed the gallbladder abnormalities in 7 of 10 patients. CONCLUSIONS: A majority of patients receiving octreotide develop gallbladder abnormalities. Ursodiol appears to reverse the abnormalities in most cases.     

Indications and limits of ultrasound-guided cytology in the management of nonpalpable thyroid nodules

PURPOSE: This report illustrates the potential diagnostic and therapeutic utility of somatostatin receptor scintigraphy and therapy with somatostatin. METHODS: In-111 pentetreotide (In-111 octreotide), a somatostatin analog, was used to define the receptor status and the extent of disease in a case of malignant thymoma. RESULTS: Subsequent treatment with nonradioactive somatostatin inhibited tumor growth. CONCLUSION: In-111 octreotide may be useful to define tumor receptor status and may provide prognostic information useful in determining subsequent therapy.     

Effects of high dose octreotide on retrograde bile salt-induced pancreatitis in rats

The effects of somatostatin and octreotide (a long acting somatostatin analogue) in acute pancreatitis are inconclusive. This study examined the prophylactic and therapeutic effects of different doses of octreotide on retrograde sodium taurodeoxycholate-induced acute necrotizing pancreatitis in rats. The rats were divided into 4 groups receiving subcutaneous injection of saline, octreotide 10 microg/kg, 20 microg/kg at 0, 8 and 16 h and octreotide 20 microg/kg at 5, 13 and 21 h, separately. The serum levels of amylase and lipase, pancreatic histopathology, mortality and hemodynamics were examined. Octreotide significantly reduced serum levels of amylase and lipase at 12 h and the degree of pancreatic edema, necrosis and hemorrhage at 18-24 h as compared to the control group. Prophylactic octreotide 10 microg/kg significantly decreased the 24-h mortality from 100% to 44.4% (p < 0.05). The 24-h mortality further reduced to 12.5% and 10% with prophylactic and therapeutic octreotide 20 microg/kg, respectively. The decrease of mean arterial pressure at 12 h was significantly lower in octreotide groups than in the control group. We conclude that octreotide improves pancreatic histopathology and survival in acute necrotizing pancreatitis in rats.     

Roles of gastrin and somatostatin in the regulation of gastric acid secretion in the fetal rabbit

In adult gastric epithelium, gastrin and somatostatin regulate parietal cell acid secretion; however, their expression and function in the fetus are largely unknown. We defined the developmental expression of gastrin and somatostatin in the fetal rabbit stomach and determined their effects on fetal acid secretion. To define peptide expression, fetuses from 12 time-mated New Zealand white rabbit does were analyzed at successive ages during the third trimester (term is 31 days). Peptides were extracted from fetal gastric tissue by boiling in water and then in acetic acid. Amidated gastrin and somatostatin levels were measured by radioimmunoassay using antisera 1296 for gastrin and 8402 for somatostatin. To determine the effects of gastrin and somatostatin, pentagastrin (64 microg/kg/hr) or octreotide (35 microg/kg/hr) were infused intravenously in conscious pregnant rabbits at 28 days of gestation for 3 hr. Fetuses (n = 45) were harvested and gastric acid was titrated with 0.02 N NaOH. Gastrin and somatostatin tissue content were 12 +/- 3 and 51 +/- 6 pmol/g at gestational day 20, respectively, and increased to 146 +/- 10 and 162 +/- 5 pmole/g by day 30 (P < 0.05). Between days 24 and 26, when gastric acid was first detectable, the molar ratio of somatostatin to gastrin decreased from 5.0 +/- 1.0 to 1.1 +/- 0.1 (P < 0.05). Fetal gastric acid content (micromole) was 28.5 +/- 1.7 in controls, 27.5 +/- 1.9 with pentagastrin treatment, and 15.8 +/- 1.4 micromole with octreotide (P < 0.05). In summary, 1) In fetal gastric tissue, gastrin increased 12-fold and somatostatin increased 3-fold between days 20 and 30 of gestation. 2) The decreased ratio of somatostatin to gastrin between days 24 and 26 of gestation coincides with the onset of fetal gastric acid secretion in the fetal rabbit. 3) Maternal administration of octreotide inhibited fetal gastric acid content; however, pentagastrin had no effect. We conclude that, in the fetal rabbit stomach, the relative expression of gastrin and somatostatin may regulate the onset of parietal cell acid secretion.     

Clinical efficacy of octreotide in the treatment of metastatic neuroendocrine tumors. A study by the Italian Trials in Medical Oncology Group

BACKGROUND: The unsatisfactory control of neuroendocrine tumor growth with chemotherapy and/or interferon (IFN-2a) stimulated us to investigate the role of the somatostatin analogue octreotide (SMS 201.995), which is reported to be highly effective in controlling carcinoid syndrome symptoms. Octreotide has been used in a wide range of doses, and it was postulated that higher doses might lead to an objective response. METHODS: The aim of the present multicenter Phase II study was to determine the safety and efficacy of SMS 201.995 in controlling carcinoids and other neuroendocrine tumors. Fifty-eight patients were treated subcutaneously with 2 sequential doses of the drug (Sandostatina, Sandoz, Inc., S.b.A. Pharmaceuticals, Basel, Switzerland). The first 23 patients received 500 micrograms 3 times a day and the remaining 35 patients received 1000 micrograms 3 times a day. The treatment was continued until the tumor progressed. RESULTS: All of the patients were adequately treated and evaluated. The predominant histotype was carcinoid, although there were instances of medullary thyroid carcinoma, pancreatic islet cell tumors, and Merkel cell carcinoma. Carcinoid syndrome was documented in 16 patients and abnormal urinary 5-hydroxyindoloacetic acid excretion in 15. The median treatment duration was 5 months (range, 2-31 months). The responses were evaluated in three categories: tumor regression for tumor growth control, symptom response, and biochemical response. There was an effect on tumor growth in two patients with carcinoids. Symptomatic control was achieved in 73% of patients and a biochemical response in 77% of patients. In twenty-seven patients, the disease stabilized for at least 6 months (range, 6-32+). The median survival time for all patients was 22 months (range, 1-32+). CONCLUSIONS: In terms of tumor regression, octreotide is disappointing (partial response: 3%); symptomatic response and biochemical control are satisfactory. These data confirm that somatostatin analogues are comparable to interferons in the treatment of carcinoid syndrome, although other efforts are necessary to control tumor regression.     

Treatment of hypersecretory ileostomy, gastrostomy and fistula of the small intestine with the somatostatin analog octreotide

Hypersecretory stomas or fistulas are disabling conditions for the patients and a therapeutic challenge to the surgeons. Octreotide treatment is reported to reduce stoma output and the need for intravenous supplements. Octreotide treatment also reduces social disability due to postprandial hypersecretion causing frequent changes of stoma systems. Two patients with high output stomas and one patient with high output ileocutaneous fistula were treated with the somatostatin analogue octreotide. Reductions in stoma or fistula output from 48 to 62% were observed.