Effect of atilmotin on gastrointestinal transit in healthy subjects: a randomized, placebo-controlled study

Structural basis for motilin and erythromycin recognition by motilin receptor

Motilin is an endogenous peptide hormone almost exclusively expressed in the human gastrointestinal (GI) tract. It activates the motilin receptor (MTLR), a class A G protein-coupled receptor (GPCR), and stimulates GI motility. To our knowledge, MTLR is the first GPCR reported to be activated by macrolide antibiotics, such as erythromycin. It has attracted extensive attention as a potential drug target for GI disorders. We report two structures of G_q-coupled human MTLR bound to motilin and erythromycin. Our structures reveal the recognition mechanism of both ligands and explain the specificity of motilin and ghrelin, a related gut peptide hormone, for their respective receptors. These structures also provide the basis for understanding the different recognition modes of erythromycin by MTLR and ribosome. These findings provide a framework for understanding the physiological regulation of MTLR and guiding drug design targeting MTLR for the treatment of GI motility disorders.

Motilin: from gastric motility stimulation to hunger signalling

After the discovery of motilin in 1972, motilin and the motilin receptor were studied intensely for their role in the control of gastrointestinal motility and as targets for treating hypomotility disorders. The genetic revolution - with the use of knockout models - sparked novel insights into the role of multiple peptides but contributed to a decline in interest in motilin, as this peptide and its receptor exist only as pseudogenes in rodents. The past 5 years have seen a major surge in interest in motilin, as a series of studies have shown its relevance in the control of hunger and regulation of food intake in humans in both health and disease. Luminal stimuli, such as bitter tastants, have been identified as modulators of motilin release, with effects on hunger and food intake. The current state of knowledge and potential implications for therapy are summarized in this Review.

A single-center, prospective, double-blind, sham-controlled, randomized study of the effect of a vibrating capsule on colonic transit in patients with chronic constipation

BACKGROUND

In an open-label study of 26 patients with IBS-C and chronic constipation, treatment with a vibrating (VIBRANT) capsule twice a week for 7.5 weeks resulted in 88.5% responders. Effects on colonic transit are unclear. We aimed to compare effects of VIBRANT and sham capsule treatment on colonic transit in patients with functional constipation.

METHODS

Patients with functional constipation (Rome III criteria) were randomized to VIBRANT or sham capsule treatment for 8 weeks and underwent scintigraphic colonic transit measurements during week 8. We estimated the overall rate of colonic transit from the slope of progression of colonic geometric center over 48 hours. The capsule was activated 8 hours after ingestion, and the vibration sequence included 240 cycles.

KEY RESULTS

There were no significant group differences in overall colonic transit [GC48, 2.76 (IQR 2.42-4.03) for sham group and 3.46 (2.55-4.61) for active treatment group (P=.13)]. Additionally, the progression of the isotope through the colon was numerically faster, though not significantly different (slope, P=.14) in the VIBRANT capsule group compared to the sham group. Three participants in the VIBRANT capsule group had accelerated colonic transit at 32 hours and faster colonic transit slope compared to the 95th percentile of the sham group.

CONCLUSIONS AND INFERENCES

Although there were no group differences between VIBRANT and sham capsule treatment on colonic transit, at least one (and possibly three) of 12 patients receiving the VIBRANT capsule had faster colonic transit. The vibration parameters to accelerate colonic transit in patients with functional constipation require further optimization.

The pharmacodynamics, safety and pharmacokinetics of single doses of the motilin agonist, camicinal, in type 1 diabetes mellitus with slow gastric emptying

BACKGROUND AND PURPOSE

Here we have investigated the pharmacokinetics, pharmacodynamics and safety of single doses of camicinal in type 1 diabetes mellitus (T1DM) patients with a history of slow gastric emptying with symptoms consistent with gastroparesis.

EXPERIMENTAL APPROACH

In a randomized, double-blind, placebo-controlled, incomplete block, three-period, two-centre crossover study, patients received oral administration of placebo and two of the three possible doses of camicinal (25, 50 or 125 mg). Gastric emptying ((13) C-octanoic acid breath test), pharmacokinetics and safety were primary outcomes.

KEY RESULTS

Nine of the 10 patients enrolled completed the study. Gastric half-emptying time decreased by -95 min (95% CI: -156.8, -34.2) after a single dose of camicinal 125 mg compared with placebo (52 vs. 147 min, P < 0.05), representing a 65% improvement. A decrease of the gastric half-emptying time compared with placebo (approximately 39 min) was observed with camicinal 25 and 50 mg, representing a 27% reduction for both doses (not statistically significant). A positive exposure-response relationship was demonstrated across all doses. The effects of camicinal on gastric half-emptying time were not influenced by fasting glucose levels. Single doses up to 125 mg were well tolerated. Camicinal was well absorbed, exhibiting linear and approximately dose-proportional pharmacokinetic characteristics and a clear exposure-response relationship with gastric emptying.

CONCLUSIONS AND IMPLICATIONS

Camicinal significantly accelerated gastric emptying of solids in T1DM patients following administration of a single oral dose. Camicinal was well tolerated and exhibited similar pharmacokinetic characteristics in diabetic patients to those previously reported in healthy volunteers.

Gastroparesis: a review of current and emerging treatment options

Gastroparesis is a motility disorder of the stomach causing delay in food emptying from the stomach without any evidence of mechanical obstruction. The majority of cases are idiopathic. Patients need to be diagnosed properly by formal testing, and the evaluation of the severity of the gastroparesis may assist in guiding therapy. Initially, dietary modifications are encouraged, which include frequent and small semisolid-based meals. Promotility medications, like erythromycin, and antiemetics, like prochlorperazine, are offered for symptom relief. In patients who are refractory to pharmacologic treatment, more invasive options, such as intrapyloric botulinum toxin injections, placement of a jejunostomy tube, or implantation of a gastric stimulator, can be considered. Hemin therapy and gastric electric stimulation are emerging treatment options that are still at different stages of research. Regenerative medicine and stem cell-based therapies also hold promise for gastroparesis in the near future.

A randomised, placebo-controlled trial comparing the effects of tapentadol and oxycodone on gastrointestinal and colonic transit in healthy humans

BACKGROUND

Tapentadol is a mu-opioid receptor agonist and norepinephrine reuptake inhibitor. In clinical trials, tapentadol provided somatic pain relief comparable to mu-opioids such as oxycodone, with significantly less gastrointestinal adverse effects. The acute effects of tapentadol on gastrointestinal and colonic transit are unclear.

AIM

To compare acute effects of oral tapentadol and oxycodone on gastric, small bowel and colonic transit of solids in 38 healthy human subjects.

METHODS

In a randomised, parallel-group, double-blind, placebo-controlled study of the effects of identical-appearing tapentadol immediate release (IR), 75 mg t.d.s., or oxycodone IR, 5 mg t.d.s., for 48 h, we measured gastric (GE), small bowel (SBT measured as colonic filling at 6 h) and colonic transit by validated scintigraphy. Drug was commenced on the evening before the start of the transit test. The primary endpoints were overall colonic transit (geometric centre, GC) at 24 h and GE half-time (t1/2 ). ancova of transit data included gender or BMI as covariates. Adverse effects were summarised.

RESULTS

At the doses tested, oxycodone and tapentadol significantly delayed GE t1/2 and SBT, but not overall colonic transit, compared to placebo. Transit profiles in all regions were not significantly different between oxycodone and tapentadol at the doses tested. Both oxycodone and tapentadol were associated with nausea and central effects attributable to central opiate effects.

CONCLUSIONS

Tapentadol significantly delayed gastric emptying t1/2 and small bowel transit, similar to oxycodone. These data suggest that acute administration of tapentadol may not have significant advantages over standard mu-opioids, in terms of the potential to avoid upper gastrointestinal motor dysfunction.

Can the intestinal dysmotility of critical illness be differentiated from postoperative ileus?

Gastrointestinal dysmotility is commonly noted in the intensive care unit and postoperative settings. Characterized by delayed passage of stool and flatus, nausea, vomiting, and abdominal distention, the condition is associated with nutritional deficiencies, risk of aspiration, and considerable allocation of health care resources. Knowledge of gastrointestinal function in health and illness continues to expand. While the factors that precipitate ileus differ between postoperative and critically ill patients, the two clinical scenarios seem to have similar mechanisms and share many of the same pathophysiologic patterns. By reviewing and comparing the literature on the respective mechanisms and contributing factors generated in these separate clinical settings, a common more comprehensive management strategy may be derived with the potential for newer innovative therapeutic options.

Treatment approaches of gastrointestinal dysfunction in Parkinson's disease, therapeutical options and future perspectives

Gastrointestinal (GI) dysfunction is a common but underestimated feature in Parkinson's disease (PD). Out of the multimodal spectrum of treatment options, there currently are only a few pharmacological treatments available to improve gastrointestinal motility and symptoms. Because enteric nervous function is mainly regulated by transmitters different from those involved in the brain, dopamine replacement is not a treatment option in PD patients. This article focuses on the known regulative mechanism of GI function and presents known and upcoming treatment options for GI dysfunction in PD.

Acute intestinal failure

PURPOSE OF REVIEW

The review aims to highlight the importance of acute gastrointestinal failure in the postoperative patient, to clarify the clinical circumstances in which acute intestinal failure complicates postoperative management, and to discuss recent advances and controversy in our understanding of the cause and pathogenesis.

RECENT FINDINGS

Acute postoperative intestinal failure ranges from a self-limiting condition of disordered intestinal peristaltic activity, through to a complex critical illness state associated with abdominal sepsis and intestinal fistulation. Recent developments have focused on the mechanisms of paralytic ileus and preventive strategies, usually as part of programmes of 'fast-track' or 'enhanced recovery' care, and on the optimum management of patients with severe abdominal sepsis, including planned versus on-demand relaparotomy, open abdominal management of severe sepsis and negative pressure wound therapy.

SUMMARY

Many cases of acute intestinal failure are preventable. Improvements in understanding and preventing paralytic ileus through changes in postoperative care may facilitate recovery of gastrointestinal function after abdominal surgery. Further and better-organized studies are needed to define the optimum strategies for treating patients with severe abdominal sepsis, managing the patient with the open abdomen and defining the role of enteral, as opposed to parenteral nutritional support in such patients.

Effect of atilmotin, a motilin receptor agonist, on esophageal, lower esophageal sphincter, and gastric pressures

BACKGROUND

Motilin, an endogenous gastrointestinal (GI) hormone, increases upper gastrointestinal tract motility and is associated with phase III of the gastric migrating motor complex. The motilin receptor agonist, atilmotin, at doses of 6, 30 or 60 microg intravenously (IV), increases the early phase of gastric emptying. Prior studies at higher doses of 100-450 microg IV demonstrated that some subjects developed noncardiac chest pain.

AIMS

The aim of this study is to determine the effects of atilmotin on esophageal, lower esophageal sphincter (LES), and gastric contractility and the development of esophageal-related symptoms.

METHODS

Ten healthy volunteers underwent esophageal manometry to study the effects of atilmotin on upper GI motility. Five subjects were studied on three separate days following administration of saline placebo and subsequent IV bolus dose of atilmotin (6, 30 or 150 microg). Another five subjects were studied at the highest dose (150 microg).

RESULTS

Atilmotin at 150 microg increased proximal gastric pressure by 6.5 mmHg (P = 0.001 compared with placebo). Atilmotin increased LES pressure at all studied doses; LES pressure increased from 24 +/- 2 mmHg following placebo injection to 34 +/- 4 mmHg following a 30 microg dose of atilmotin (P = 0.007). In the esophagus, atilmotin increased the percentage of failed swallows at the highest dose studied. Failed swallows increased from 17 +/- 7% following placebo injection to 36 +/- 7% following a 150 microg dose of atilmotin (P = 0.016). Atilmotin decreased distal esophageal contractile amplitude only at the highest dose studied, from 69 +/- 8 mmHg (placebo) to 50 +/- 5 mmHg following 150 microg atilmotin (P = 0.018). There were no serious adverse effects or episodes of chest pain with atilmotin.

CONCLUSIONS

Atilmotin affects esophageal, LES, and gastric motility. LES and gastric pressures were increased, whereas there was disruption of esophageal peristalsis characterized by lower amplitude and failed contractions.

Colonic transit studies: normal values for adults and children with comparison of radiological and scintigraphic methods

The sitz or plastic marker study for colonic transit has been around for many years. It is applicable where an X-ray machine exists, is widely used and is accepted as the gold standard for diagnosing constipation. Recently, radiopharmaceutical methods have been developed. The theme of this review is their possible roles in the assessment of paediatric bowel motility disorders in patients presenting to paediatric surgeons. This review presents data on total and segmental transit in normal adults and children and comparing the two techniques in adults. Reliability and reproducibility are presented. Normative data for colonic transit in adults and children are discussed and parameters for assessing abnormal transit are reviewed. Normal colonic transit takes 20-56 h. Plastic marker studies are more readily accessible, but the assessment may be misleading with current methods. Plastic markers show faster transit than scintigraphy. It is difficult to compare the two techniques because methods of reporting are different. Using scintigraphy, repeatability is good. Separation of normal from slow transit in the ascending colon is apparent at 24 and 48 h, but the determination of transit through the distal colon/rectum in adults may require studies of more than 7 days. In conclusion, plastic marker studies and scintigraphy show similar transit rates in young adults and children. However, scintigraphy has advantages of allowing transit through the stomach and small intestine to be measured and has proved useful in the diagnostic workup of children with intractable constipation.

Gastroparesis: Current diagnostic challenges and management considerations

Gastroparesis refers to abnormal gastric motility characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common etiologies include diabetes, post-surgical and idiopathic. The most common symptoms are nausea, vomiting and epigastric pain. Gastroparesis is estimated to affect 4% of the population and symptomatology may range from little effect on daily activity to severe disability and frequent hospitalizations. The gold standard of diagnosis is solid meal gastric scintigraphy. Treatment is multimodal and includes dietary modification, prokinetic and anti-emetic medications, and surgical interventions. New advances in drug therapy, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. In this comprehensive review, we discuss gastroparesis with emphasis on the latest developments; from the perspective of the practicing clinician.

New therapies in the treatment of postoperative ileus after gastrointestinal surgery

Postoperative ileus after gastrointestinal surgery results from many factors, including the effects of surgical trauma, anesthetic agents, hyperactivity of the sympathetic nervous system, local inflammatory reactions, and the use of opioids in the postoperative period. Postoperative ileus can lead to potential complications and may prolong patients' hospitalization, thereby leading to an increase in healthcare costs. There have been recent efforts to improve the understanding of the pathogenesis of postoperative ileus and to develop new treatments to prevent or minimize its occurrence. Here, we present a review of the factors related to the development of postoperative ileus and new therapies directed at its prevention.

Hormones of the gut-brain axis as targets for the treatment of upper gastrointestinal disorders

The concept of the gut forming the centre of an integrated gut-brain-energy axis - modulating appetite, metabolism and digestion - opens up new paradigms for drugs that can tackle multiple symptoms in complex upper gastrointestinal disorders. These include eating disorders, nausea and vomiting, gastroesophageal reflux disease, gastroparesis, dyspepsia and irritable bowel syndrome. The hormones that modulate gastric motility represent targets for gastric prokinetic drugs, and peptides that modify eating behaviours may be targeted to develop drugs that reduce nausea, a currently poorly treated condition. The gut-brain axis may therefore provide a range of therapeutic opportunities that deliver a more holistic treatment of upper gastrointestinal disorders.

[Gastroparesis and its treatment options]

Gastroparesis is a disorder of gastric emptying that occurs in the absence of mechanical obstruction. Its cardinal features include nausea, vomiting, bloating, early satiety and discomfort. Weight loss, dehydration, electrolyte disturbances and malnutrition may develop in severe cases. The majority of cases is idiopathic, long standing diabetes mellitus is responsible for about 25-30% of cases. Diabetic gastroparesis may render glucose control extremely difficult, its treatment represents a major challenge. Besides frequent, small meals and psychological support, several drug options are available, however, their efficacy is limited and only a few randomized studies have been performed to date. Prokinetic agents (erythromycin, domperidone, metoclopramide) and antiemetics (phenothiazines, serotonin antagonists, butyrophenones) are the most wide-spread medicaments. Among the novel, recently developed agents, 5-HT4 serotonin receptor agonists and dopamine D2 receptor antagonists are the most promising. Injection of botulinum toxin into the pyloric sphincter resulted in faster gastric emptying and symptom alleviation in some studies. Gastric electric stimulation appears to be one of the most effective options, both low and high-frequency stimulation may alleviate symptoms. Gastrostomy/jejunostomy and other surgical interventions are considered as "last resort".

Motilin

PURPOSE OF REVIEW

Motilin is a hormone produced from endocrine cells of the duodenal mucosa to help regulate motility of the digestive tract. This review discusses new findings on the potential impact of motilin in human medicine.

RECENT FINDINGS

Motilin is a member of the peptide family that includes ghrelin whose cDNA also encodes a new candidate peptide, obestatin. Physiological interactions between these products will have to be explored. Pharmacological agents, agonists as well as antagonists, to motilin receptors are now emerging for clinical application. Motilin-receptor characterization, regarding its localization on nerves or muscles, as well as its biochemical mechanisms to sensitization for example, will be important steps in the design of future motilin agonists or antagonists.

SUMMARY

Motilin is a fascinating hormone for the physiologist. Its interaction with the family member ghrelin and with obestatin will open new areas for basic research. Motilin-receptor agonists or antagonists could soon be part of the therapeutic arsenal of the clinician to improve digestive dysmotility.

Standardized concept for the treatment of gastrointestinal dysmotility in critically ill patients--current status and future options

Inhibition of gastrointestinal motility is a major problem in critically ill patients. Motor stasis gives rise to subsequent complications including intolerance to enteral feeding, enhanced permeability of the atrophic intestinal mucosa and conditions as severe as systemic inflammatory response syndrome, sepsis and multiple organ failure. Although the diagnosis of motility disturbances in critically ill patients is difficult, the type and site of the disturbance are important to consider in the analysis of the condition and in the choice of therapeutic approach. The pharmacological treatment of impaired gastrointestinal motility is difficult to handle for the clinician, because the underlying mechanisms are complex and not fully understood and the availability of pharmacological treatment options is limited. In addition, there is a lack of controlled studies on which to build an evidence-based treatment concept for critically ill patients. Notwithstanding this situation, there has been remarkable progress in the understanding of the integrated regulation of gastrointestinal motility in health and disease. These advances, which largely relate to the organization of the enteric nervous system and its signaling mechanisms, enable the intensivist to develop a standardized concept for the use of prokinetic agents in the treatment of impaired gastrointestinal motility in critically ill patients.

Severe gastroparesis: new treatment alternatives

Dopamine antagonists, such as metoclopramide and domperidone, and the motilin receptor agonist erythromycin have been the cornerstones in drug treatment of severe gastroparesis for more than a decade. No new drugs have been approved for treatment of this disorder in this period. Instead, the 5-HT4 agonist cisapride has been withdrawn due to side-effects. The effectiveness of intrapyloric botulinum toxin for gastroparesis remains to be shown. In the last decade, gastric electrical stimulation (GES) with a fully implantable device has evolved as a promising treatment, with significant effects on nausea and vomiting in most patients with severe, drug-refractory diabetic gastroparesis and postsurgical gastroparesis. A proportion of patients with severe idiopathic gastroparesis and patients with idiopathic nausea and vomiting also respond. More research is needed to achieve precise selection of responders/non-responders to GES, and to study the potential benefit of GES in other patient groups suffering from severe nausea or vomiting.

Mitemcinal (GM-611), an orally active motilin agonist, facilitates defecation in rabbits and dogs without causing loose stools

The effects of mitemcinal (GM-611), an orally active motilin agonist, on defecation were investigated in rabbits and dogs. In normal rabbits, within 0-3 h of dosing, orally administered mitemcinal (2.5-10 mg kg(-1)) increased stool weight in a dose-dependent manner without causing loose stools. Sennoside (12-48 mg kg(-1)) also facilitated defecation within 2-9 h of oral administration, but the stools were significantly loosened. In the morphine-induced constipation model, the stool weight of morphine-treated rabbits (1 mg kg(-1)) was only 37.5% of that of untreated animals. Mitemcinal (0.5-20 mg kg(-1)) dose-dependently increased stool weight without increasing stool water content. At the highest dose of mitemcinal, stool weight recovered to 83.9% of that of untreated animals. In normal dogs, mitemcinal (0.3-3 mg kg(-1)) reduced the time to first bowel movement after oral administration without inducing diarrhoea at any dose. These results indicate that mitemcinal facilitates defecation without inducing severe diarrhoea. It is suggested that mitemcinal may be a novel therapeutic agent for constipation that enables easier control of the timing of defecation because of the early onset and short duration of its action, compared with sennoside.

Differences between the abilities of tegaserod and motilin receptor agonists to stimulate gastric motility in vitro

BACKGROUND AND PURPOSE

Motilin or 5-HT4 receptor agonists stimulate gastrointestinal motility. Differences in activity are suggested but direct comparisons are few. A method was devised to directly compare the gastric prokinetic activities of motilin, the motilin receptor agonist, erythromycin, and the 5-HT4 receptor agonist, tegaserod.

EXPERIMENTAL APPROACH

Gastric prokinetic-like activity was assessed by measuring the ability to facilitate cholinergically-mediated contractions evoked by electrical field stimulation (EFS) in rabbit isolated stomach. Comparisons were made between potency, maximal activity and duration of responses.

KEY RESULTS

Rabbit motilin (r.motilin) 0.003-0.3 microM, [Nle13]motilin 0.003-0.3 microM, erythromycin 0.3-10 microM and tegaserod 0.1-10 microM caused concentration - dependent potentiation of EFS-evoked contractions. The potency ranking was r.motilin = [Nle13]motilin > tegaserod > erythromycin. The Emax ranking was r.motilin = [Nle13]motilin = erythromycin > tegaserod. Responses to r.motilin and [Nle13]motilin faded rapidly (t1/2 9 and 11 min, respectively) whereas those to erythromycin and tegaserod were maintained longer (t1/2 24 and 28 min). The difference did not appear to be due to peptide degradation. A second application of [Nle13]motilin was excitatory after 60 min contact and fade of the initial response (responses to 0.03 and 0.1 microM [Nle13]motilin were not different from those caused by the first application).

CONCLUSIONS AND IMPLICATIONS

Prokinetic-like activities of the 5-HT4 agonist tegaserod and the motilin receptor agonists were compared by measuring changes in cholinergically-mediated contractions. This novel approach highlighted important differences between classes (greater Emax of motilin, compared with tegaserod) and for the first time, within each class (short t1/2 for motilin, compared with erythromycin).

Pathophysiology and management of diabetic gastropathy: a guide for endocrinologists

Delayed gastric emptying is frequently observed in patients with long-standing type 1 and type 2 diabetes mellitus, and potentially impacts on upper gastrointestinal symptoms, glycaemic control, nutrition and oral drug absorption. The pathogenesis remains unclear and management strategies are currently suboptimal. Therapeutic strategies focus on accelerating gastric emptying, controlling symptoms and improving glycaemic control. The potential adverse effects of hyperglycaemia on gastric emptying and upper gut symptoms indicate the importance of normalising blood glucose if possible. Nutritional and psychological supports are also important, but often neglected. A number of recent pharmacological and non-pharmacological therapies show promise, including gastric electrical stimulation. As with all chronic illnesses, a multidisciplinary approach to management is recommended, but there are few data regarding long-term outcomes.

Pharmacodynamic effects of a novel prokinetic 5-HT receptor agonist, ATI-7505, in humans

ATI-7505, an investigational 5-HT(4) receptor agonist, was designed to have similar activity as cisapride without the cardiac adverse effects, i.e. without QT prolongation. In addition, ATI-7505 is not metabolized by CYP450. The aim of the study was to assess the effect of ATI-7505 on gastrointestinal (GI) and colonic transit in healthy humans. A randomized, parallel-group, double-blind, placebo-controlled study evaluated effects of 9-day treatment with ATI-7505 (3, 10 or 20 mg t.i.d.) on scintigraphic GI and colonic transit in healthy volunteers (12 per group). Primary endpoints were gastric-emptying (GE) T(1/2), colonic geometric centre (GC) at 24 h and ascending colon (AC) emptying T(1/2). Daily stool diaries were kept. Analysis of covariance assessed overall treatment group differences, followed by post hoc unadjusted pairwise comparisons. There were borderline overall treatment effects (decrease) on GE T(1/2) (P = 0.154); the 20 mg t.i.d. of ATI-7505-accelerated GE vs placebo (P = 0.038). ATI-7505 increased colonic transit (GC24, P = 0.031) with fastest transit at 10 mg t.i.d. vs placebo (P = 0.065). ATI-7505 accelerated AC emptying T(1/2) (overall P = 0.075) with 10 mg dose vs placebo (P = 0.042). There was looser stool (Bristol stool form scale, overall P = 0.056) with the 10 and 20 mg t.i.d. doses. No safety issues were identified. ATI-7505 accelerates overall colonic transit and tends to accelerate GE and AC emptying and loosen stool consistency.

An update on autonomic neuropathy affecting the gastrointestinal tract

Gastrointestinal symptoms and disordered gut motility occur frequently in the diabetic population and are generally regarded as manifestations of gastrointestinal "autonomic dysfunction," although the relationships between both symptoms and dysmotility with abnormal cardiovascular autonomic function are weak. It is now recognized that the blood glucose concentration is both a determinant of and determined by gastrointestinal function. An improved definition of the underlying pathophysiology should facilitate the development of therapies that are targeted more effectively.