Effect of the long-acting somatostatin analogue SMS 201-995 on small-intestinal interdigestive motility in the dog

Medical management of malignant bowel obstruction in patients with advanced cancer: 2021 MASCC guideline update

BACKGROUND

Malignant bowel obstruction (MBO) is a frequent complication in patients with advanced cancer, particularly colon or gynecological malignancies. MASCC previously published a guideline for symptom management of MBO in 2017. This is a 5-year update.

METHOD

A systematic search and review of relevant literature includes a review published in 2010 and 2017. The guideline update used the same literature search process as followed in 2015. The dates of the new search included 2015 up to February 2, 2021. The guidelines involved the pharmacologic management of nausea and vomiting in malignant bowel obstruction (MBO) only. Only randomized trials were included in the updated guideline as evidence. The evidence was reviewed by the panel and the MASCC criteria for establishing a guideline were followed using MASCC level of grading and category of evidence.

RESULTS

There was one systematic review and 3 randomized trials accepted as evidence from 257 abstracts. Octreotide is effective in reducing gastrointestinal secretions and colic and thereby reduces nausea and vomiting caused by MBO. Scopolamine butylbromide is inferior to octreotide in the doses used in the comparison study. Olanzapine or metoclopramide may be effective in reducing nausea and vomiting secondary to partial bowel obstructions. The panel suggests using either drug. Additional studies are needed to clarify benefits. Haloperidol has been used by convention as an antiemetic but has not been subjected to a randomized comparison. Ranitidine plus dexamethasone may be effective in reducing nausea and vomiting from MBO but cannot be recommended until there is a comparison with octreotide.

DISCUSSION

Octreotide remains the drug of choice in managing MBO. Ranitidine was used in one randomized trial in all participants and so its effectiveness as a single drug is not known until there is a randomized comparison with octreotide. Antiemetics such as metoclopramide and olanzapine may be effective, but we have very few randomized trials of antiemetics in MBO.

CONCLUSION

The panel recommends octreotide in non-operable MBO. Randomized trials are needed to clarify ranitidine and antiemetic choices.

Effect of octreotide on gastrointestinal motility in children with functional gastrointestinal symptoms

BACKGROUND

The somatostatin analogue octreotide has been proposed as a possible therapeutic agent in patients with abnormal gastrointestinal motility. This study was conducted to study the effects of 0.5 microg/kg and 1.0 microg/kg subcutaneous octreotide on antroduodenal motility in children with chronic gastrointestinal disorders.

METHODS

Twenty-three children were studied, eight with intestinal pseudo-obstruction, six with nonulcer dyspepsia, six with gastroesophageal reflux disease, and three with intractable constipation. After recording fasting motility for more than 4 hours, the children were randomized to receive 0.5 microg/kg or 1 microg/kg of subcutaneous octreotide. Motility was recorded for another hour after feeding in 12 children.

RESULTS

Phase III of the motor migrating complex was present in 13 of 23 children before and in 21 after octreotide (p < 0.02). All phase III episodes after administration of octreotide except one originated in the small intestine. Phase IIIs after octreotide were longer and were propagated faster than the spontaneous phase IIIs. There were no antral contractions during fasting after octreotide. There was a significant decrease in phase II intestinal motor activity in the hour after administration of octreotide (p < 0.001). There was no difference in effect between the two doses. After feeding, antral contractions were present in all children, and intestinal phase IIIs were not abolished.

CONCLUSIONS

In children with chronic bowel disorders, subcutaneous octreotide induced phase IIIs that differed from spontaneous phase IIIs and were not inhibited by meals. Octreotide decreased antral motility during fasting and inhibited intestinal phase II. Feeding abolished the inhibitory effect of octreotide on antral motility.

Effect of octreotide and erythromycin on idiopathic and scleroderma-associated intestinal pseudoobstruction

Treatment of chronic intestinal pseudoobstruction with prokinetic agents has been disappointing. Our study was designed to determine if octreotide and erythromycin would provide sustained relief from nausea, abdominal pain, and bloating in pseudoobstruction. Using gastrointestinal manometry, quantitative parameters of the activity front of the migrating motor complex at baseline and after prokinetic therapy with erythromycin and octreotide were determined in 14 patients with intestinal pseudoobstruction who had nausea, abdominal pain, and bloating. Patients were treated with erythromycin and octreotide for 20-33 weeks. Octreotide increased the frequency, duration, and motility index of activity fronts (AFs) from 1.2 +/- 0.3 AFs/4 hr, 2.7 +/- 0.7 min, and 85 +/- 23 min mm Hg to 4.1 +/- 0.8 AFs/4 hr, 5.5 +/- 0.7 min, and 152 +/- 24 min mm Hg, respectively (P < 0.05). Antral activity was decreased from 63 +/- 14 to 23 +/- 8% by octreotide (P < 0.05). Erythromycin induced antral activity; however, small intestinal motor activity was suppressed. While on erythromycin and octreotide, five patients had long-term improvement of nausea and abdominal pain. All responders had at least 5 AFs/4 hr induced by octreotide. We conclude that octreotide and erythromycin relieve abdominal pain and nausea in pseudoobstruction. Patients who have at least 5 AFs/4 hr after octreotide administration are most likely to clinically respond.

Octreotide does not prevent bacterial translocation in an infant piglet model of intestinal ischemia-reperfusion

The process of bacterial translocation (BT) after ischemia/reperfusion (I/R) injury is reported to be mediated by local mucosal factors, the effects of pancreatic enzymes, epithelial disruption, and by dysfunctional intestinal motility. Octreotide (OCT), a somatostatin analog, has been postulated to protect against BT by influencing one or more of these factors. Twenty-two formula-fed piglets (weight, 3.5 +/- 0.5 kg; age, 20 +/- 5 days) were divided into four groups: control (no drug given; no I/R; n = 6), I/R (no drug given; n = 5), I/R plus low-dose OCT (LD OCT, 0.08 microgram/kg; n = 6), and I/R plus high-dose OCT (HD OCT, 8 micrograms/kg; n = 5). All experimental subjects had nonocclusive mesenteric ischemia induced by reversible pericardial tamponade with mesenteric flow decreased to 25 +/- 5% of baseline for 5 hours followed by 15 +/- 5 hours of reperfusion. Mesenteric lymph nodes (MLN), liver, spleen, blood, and peritoneum were harvested for blind microbial analysis. None of the animals in the control group experienced translocation to the tissues tested. All of the animals in the I/R group experienced BT to the MLN. The subjects in the LD OCT and HD OCT groups experienced BT to the MLN 66% and 80% of the time, respectively. Despite the reported clinical evidence that OCT can protect the intestinal mucosa from injury and increase the clearance of bacteria from the gastrointestinal tract, in this study in which variables other than I/R known to promote bacterial translocation were eliminated, OCT failed to modify or prevent the occurrence of translocation to the MLN after I/R injury.

Differential regional effects of octreotide on human gastrointestinal motor function

The effects of octreotide on regional motor function in the human gut are unclear. In a randomised, blinded study the effects of octreotide (50 micrograms, subcutaneously, three times daily) and placebo on gastric, small bowel, and colonic transit, and colonic motility and tone were assessed in 12 healthy volunteers whose colon had been cleansed. Octreotide accelerated initial gastric emptying (p = 0.05), inhibited small bowel transit (p < 0.01), and reduced ileocolonic bolus transfers (p < 0.05). Colonic transit was unaltered by octreotide; the postprandial colonic tonic response was inhibited (p < 0.05 v placebo), whereas colonic phasic pressure activity was increased by octreotide (p < 0.05 v placebo). These data support the use of octreotide in diarrhoeal states but not in diseases that cause small bowel stasis and bacterial overgrowth. Simultaneous measurements of colonic transit, tone, and phasic contractility are valid in studying the effects of pharmacological changes and may be applicable to the study of the human colon in health and disease.

Amelioration of intestinal dysmotility and stasis by octreotide early after small-bowel autotransplantation in dogs

BACKGROUND

Intestinal dysmotility and stasis after intestinal transplantation are considered to promote bacterial overgrowth and translocation. Two prokinetic agents, KW5139 (13-leu-motilin) and the somatostatin analogue octreotide acetate, were studied to determine whether they can ameliorate intestinal dysmotility during the early postoperative period.

MATERIALS AND METHODS

Motility was recorded by multiple extraluminal strain-gauge transducers in 6 dogs on postoperative days 1, 3, 7, and 14. A barium meal study was performed with a separate group of 8 dogs on postoperative days 3 and 7.

RESULTS

The agent KW5139 induced brief, weak contractions in the graft and had little effect on the dilated bowel; however, octreotide induced motor activity that propelled accumulated intestinal contents into the colon and reduced dilation of the transplanted bowel.

CONCLUSION

Octreotide, but not KW5139, ameliorates intestinal dysmotility associated with bowel autotransplantation during the early postoperative period. Short-term administration of octreotide may be useful for the treatment of dysmotility following intestinal transplantation.

Expanding uses of octreotide

This chapter reviews the therapeutic use of octreotide in a variety of pancreatic disorders, including acute pancreatitis, in the prevention of postoperative and post-ERCP pancreatitis, in the control of postoperative pancreatic fistulae, and in chronic pancreatitis for the control of pain and of pseudocysts and ascites. The review also discusses the use of octreotide in intestinal disorders of motility, gastrointestinal bleeding, intestinal fistulae and refractory diarrhoea, including the diarrhoeas of AIDS, diabetes, short gut, chemotherapy, ileostomy and gastric surgery. The use of octreotide in neuroendocrine tumours, both for therapy and diagnostic imaging, is reviewed briefly. The paucity of adequately controlled studies in many of these situations is indicated and the potential usefulness of octreotide estimated.

A somatostatin analogue inhibits afferent pathways mediating perception of rectal distention

BACKGROUND

Octreotide, a somatostatin analogue, has antinociceptive activity in several models. We studied whether octreotide modifies perception of rectal distention in healthy volunteers and examined its mechanism of action.

METHODS

Octreotide (100 micrograms, subcutaneously) and placebo were injected in double-blind fashion. Rectal balloons measured volumes that evoked increasing levels of perception. Octreotide's effects on rectal sensation were compared with actions on rectal resistance, rectal motor activity, afferent and efferent anal activity, and somatic perception.

RESULTS

After octreotide administration, threshold perception, pressure, urgency, and maximal tolerated volume were reported at 62 +/- 4, 185 +/- 11, 269 +/- 17, and 362 +/- 25 mL, which were greater than after administration of placebo (25 +/- 4, 95 +/- 9, 153 +/- 10, and 211 +/- 13 mL, P < 0.01). Rectal pressures, which increased from 9.2 +/- 1.2 mm Hg at 30 mL to 20.2 +/- 1.7 mm Hg at 180 mL after administration of placebo, were not modified by octreotide; this shows a lack of effect on rectal resistance. However, in addition to enhancing volumetric tolerance, maximally tolerated pressures were increased to 42.4 +/- 5.1 mm Hg (P < 0.01) by octreotide. Octreotide increased phasic rectal contractions but did not change anal pressures or block the rectoanal inhibitory reflex, confirming that local rectal reflex arcs are unaffected. Perception of thermal or electrical cutaneous stimulation was unaffected by octreotide showing selectivity for visceral afferent pathways.

CONCLUSIONS

Octreotide reduces sensation of rectal distention via inhibition of visceral afferent pathways. In contrast, afferent pathways involved in local reflexes and cutaneous perception are not inhibited by octreotide.

Pharmacodynamic effects of Sandostatin in the gastrointestinal tract

Somatostatin (SST) is widely distributed throughout the human gastrointestinal system. There, it is found in neurons and fibers of both the submucosal and myenteric plexus and the pancreas, and also in the D cells of the stomach, gut, and pancreatic islets. Whereas in the intestinal nervous system, duodenum, and pancreas, somatostatin-14 (SST-14) appears to be the predominant molecular form, the endocrine-type D cells of the intestine primarily contain somatostatin-28 (SST-28). SST peptides may act very differently at different sites, as hormones, paracrine substances, or neurotransmitters. Because of this complexity of action, very little is known about the physiological effects of SST in the gastrointestinal tract. In contrast, the pharmacological actions of natural synthetic SST have been thoroughly studied and have given rise to many therapeutic applications. Octreotide, an analogue with a longer half-life and higher potency, has greatly facilitated the clinical application of SST. This review deals with the pharmacological effects of octreotide on different gastrointestinal functions. The SST analogue exerts a long-lasting inhibitory action on gastric acid, pancreatic enzyme, bicarbonate secretion, and on bile flow. It also inhibits stimulated intestinal secretion, ie, the release of neuropeptides from the gut and pancreas. It can also prolong orocecum transit time and prevent gallbladder contraction. It inhibits absorption of nutrients and exerts inhibitory effects on splanchnic hemodynamics. It is because of these actions that SST has attracted so much attention in the treatment of different gastrointestinal disorders.

Effect of octreotide on intestinal motility and bacterial overgrowth in scleroderma

BACKGROUND

Patients with scleroderma may have abnormal motility of the small intestine, with pseudoobstruction and bacterial overgrowth. Standard stimulatory agents are often ineffective in such patients. Because the somatostatin analogue octreotide evokes intestinal motor activity in normal subjects, we hypothesized that it might increase motility in patients with scleroderma.

METHODS

We studied the effects of octreotide on intestinal motility and plasma motilin concentrations in five fasting patients with scleroderma who had bacterial overgrowth and in six fasting normal subjects. The motor effects of octreotide were correlated with its effects on abdominal symptoms and bacterial overgrowth as determined by the level of breath hydrogen excretion.

RESULTS

In the normal subjects, octreotide (10 micrograms subcutaneously) increased the mean (+/- SD) frequency of intestinal migrating complexes, which reflect intestinal motility, from 1.5 +/- 1.0 to 4.1 +/- 1.1 every three hours. In the patients with scleroderma, who had no spontaneous migrating complexes, octreotide (100 micrograms) induced 3.6 +/- 2.3 complexes every three hours. These complexes propagated at the same velocity and had two-thirds the amplitude of the spontaneous complexes in normal subjects. Plasma motilin concentrations, which were higher in the patients with scleroderma (229 +/- 74 pmol per liter) than in the normal subjects (112 +/- 37 pmol per liter), were inhibited by octreotide, suggesting that intestinal activity evoked by octreotide is independent of motilin. Treatment of the patients with scleroderma with octreotide (50 micrograms every evening) for three weeks reduced breath hydrogen excretion while they were fasting from 25 +/- 5 to 4 +/- 2 ppm (P = 0.001) and breath hydrogen excretion after they ingested 50 g of glucose from 46 +/- 24 to 8 +/- 7 ppm (P = 0.015); these reductions were accompanied by a significant decrease in nausea, bloating, and abdominal pain and by less frequent emesis.

CONCLUSIONS

Octreotide stimulates intestinal motility in normal subjects and in patients with scleroderma. In such patients, the short-term administration of octreotide reduces bacterial overgrowth and improves abdominal symptoms. This agent may be useful for the treatment of intestinal dysmotility in patients with scleroderma.