Erythromycin and other macrolides as prokinetic agents

Gastroesophageal reflux disease in children: What’s new right now?

Gastroesophageal reflux (GER) in children is very common and refers to the involuntary passage of gastric contents into the esophagus. This is often physiological and managed conservatively. In contrast, GER disease (GERD) is a less common pathologic process causing troublesome symptoms, which may need medical management. Apart from abnormal transient relaxations of the lower esophageal sphincter, other factors that play a role in the pathogenesis of GERD include defects in esophageal mucosal defense, impaired esophageal and gastric motility and clearance, as well as anatomical defects of the lower esophageal reflux barrier such as hiatal hernia. The clinical manifestations of GERD in young children are varied and nonspecific prompting the necessity for careful diagnostic evaluation. Management should be targeted to the underlying aetiopathogenesis and to limit complications of GERD. The following review focuses on up-to-date information regarding of the pathogenesis, diagnostic evaluation and management of GERD in children.

Comparative Effectiveness of Intravenous Azithromycin Versus Erythromycin Stimulating Antroduodenal Motility in Children

BACKGROUND

Azithromycin has been shown to improve gastrointestinal motility in adults and may have fewer drug interactions and reduced arrhythmogenic effects than erythromycin. We hypothesized that azithromycin is comparable to erythromycin in eliciting pharmacodynamic outcomes for antral and small bowel motility.

OBJECTIVE

To compare the pharmacodynamic effectiveness of azithromycin and erythromycin for eliciting antral and duodenal motility in pediatric patients who underwent antroduodenal manometry for different indications.

METHODS

We conducted a retrospective comparison of clinic data and manometric pharmacodynamics outcomes in patients who underwent antroduodenal manometry between 2013 and 2017.

RESULTS

Fifty-one patients mean age (± standard deviation) 9.7 (5.4) years, received either azithromycin 3 mg/kg (n = 20) or erythromycin 2 mg/kg (n = 31) during antroduodenal manometry. For patients receiving erythromycin, mean area under the curve (AUC) across all eight pressure ports increased from median [95% confidence interval] 2256 [1585, 2602] to 8742 [5876, 11761] mmHg × s (P < 0.001) and mean motility index increased from 8.63 [7.87, 9.42] to 11.98 [11.20, 12.21] (P < 0.001). For patients receiving azithromycin, mean AUC increased from 2255 [1585, 2602] to 8254 [5649, 10470] mmHg × s (P < 0.001) and motility index increased from 8.63 [7.87,9.42] to 11.79 [11.03, 12.21] (P < 0.001). Neither mean stimulated AUC nor mean motility index was significantly different between azithromycin and erythromycin treatments. There was no significant difference in side effects between groups.

CONCLUSIONS

Azithromycin and erythromycin have similar pharmacodynamic effects on antral and small bowel contractility in children. Azithromycin should be considered an acceptable alternative to erythromycin as an upper gastrointestinal tract prokinetic for children and has historically had fewer side effects than erythromycin.

Foregut Dysmotility in the Lung Transplant Patient

PURPOSE OF REVIEW

To explore the role of upper gastrointestinal disease in the clinical course of lung transplant patients - including its pathophysiology, diagnostic testing, and treatment options.

RECENT FINDINGS

Gastroesophageal reflux disease (GERD) and foregut motility disorders are more prevalent among end-stage lung disease patients and are associated with poorer outcomes in lung transplant recipients. A proposed mechanism is the exposure of the lung allograft to aspirated contents, resulting in inflammation and rejection. Diagnostic tools to assess for these disorders include multichannel intraluminal impedance and pH (MII-pH) testing, high resolution esophageal manometry (HREM), and gastric emptying scintigraphy. The main treatment options are medical management with acid suppressants and/or prokinetic agents and anti-reflux surgery. In particular, data support the use of early anti-reflux surgery to improve outcomes. Newer diagnostic tools such as MII-pH testing and HREM allow for the identification of both acid and non-acid reflux and esophageal motility disorders, respectively. Recent studies have demonstrated that early anti-reflux surgery within six months post-transplant better protects against allograft injury and pulmonary function decline when compared to late surgery. However, further prospective research is needed to evaluate the short and long-term outcomes of these diagnostic approaches and interventions.

Effects of parenteral administration of tylosin and ivermectin on abomasal emptying rate in healthy suckling lambs by use of nuclear scintigraphy

Abomasal hypomotility is one of the important causes of neonatal mortality in small ruminants. Various pharmaceutical agents have been studied to address this problem in large ruminants. The aim of this study was to determine the effect of parenteral administration of tylosin and ivermectin on abomasal emptying rate in neonatal suckling lambs. Abomasal emptying rate was assessed using nuclear scintigraphic method in 10 healthy female Iranian fat tailed Ghezel lambs. Each lamb was tested three times, once as a control (1 ml of saline 0.9%, IM) and twice after the injection of tylosin (17.6 mg/kg, IM) and ivermectin (200 μg/kg, SC) in a crossover study. Based on radiopharmaceutical counts, remnant activity in abomasums at 90 min were 48.3 ± 3.5, 45.6 ± 7.5 and 41.6 ± 2.9% in control, tylosin and ivermectin groups, respectively. Administration of tylosin (p = 0.049) and ivermectin (p = 0.045) to lambs, significantly caused faster abomasal emptying rate compared to control. Evaluating the ROIs revealed that the half emptying time (T_1/2) in control, tylosin and ivermectin groups were 67.1 ± 8.6, 62.6 ± 14.2 and 54.3 ± 9.9 min, respectively. These difference between all groups, statistically were significant (p = 0.026). However, the clinical efficacy of abomasal emptying rate facilitating by tylosin or ivermectin administration in lambs remains to be determined.

Esophageal Evaluation for Patients Undergoing Lung Transplant Evaluation: What Should We Do for Evaluation and Management

Lung transplantation is a high-risk, but lifesaving, procedure for patients with end-stage lung disease. Although 1-year survival is high, long-term survival is not nearly as high, due mainly to acute and chronic rejection. Bronchiolitis obliterans syndrome is the most common type of chronic rejection and often leads to poor outcomes. For this reason, esophageal testing in the lung transplant population has become a major issue, and this article discusses the evidence behind esophageal testing, the importance of esophageal dysmotility gastroesophageal reflux disease, both acidic and nonacidic reflux, and aspiration and the treatment of these findings.

Diabetic Gastroparesis

This review covers the epidemiology, pathophysiology, clinical features, diagnosis, and management of diabetic gastroparesis, and more broadly diabetic gastroenteropathy, which encompasses all the gastrointestinal manifestations of diabetes mellitus. Up to 50% of patients with type 1 and type 2 DM and suboptimal glycemic control have delayed gastric emptying (GE), which can be documented with scintigraphy, 13C breath tests, or a wireless motility capsule; the remainder have normal or rapid GE. Many patients with delayed GE are asymptomatic; others have dyspepsia (i.e., mild to moderate indigestion, with or without a mild delay in GE) or gastroparesis, which is a syndrome characterized by moderate to severe upper gastrointestinal symptoms and delayed GE that suggest, but are not accompanied by, gastric outlet obstruction. Gastroparesis can markedly impair quality of life, and up to 50% of patients have significant anxiety and/or depression. Often the distinction between dyspepsia and gastroparesis is based on clinical judgement rather than established criteria. Hyperglycemia, autonomic neuropathy, and enteric neuromuscular inflammation and injury are implicated in the pathogenesis of delayed GE. Alternatively, there are limited data to suggest that delayed GE may affect glycemic control. The management of diabetic gastroparesis is guided by the severity of symptoms, the magnitude of delayed GE, and the nutritional status. Initial options include dietary modifications, supplemental oral nutrition, and antiemetic and prokinetic medications. Patients with more severe symptoms may require a venting gastrostomy or jejunostomy and/or gastric electrical stimulation. Promising newer therapeutic approaches include ghrelin receptor agonists and selective 5-hydroxytryptamine receptor agonists.

Erythromycin and Reflux Events in Premature Neonates: A Randomized Clinical Trial

OBJECTIVE

Gastroesophageal reflux disease (GERD) in premature neonates may manifest as apnea, bradycardia, growth failure, aspiration, or feeding intolerance. Erythromycin ethylsuccinate (EES), is often used as a pro-kinetic in the management of GERD, despite lack of evidence or safety from randomized controlled trials. We sought to study the efficacy of enteral EES at a dose of 50 mg · kg · day in decreasing the frequency of gastroesophageal reflux events as determined by pH-multichannel intraluminal impedance (pH-MII) monitoring.

METHODS

In a randomized, double-blind, placebo-controlled trial, eligible premature neonates with clinical signs of GERD underwent 24-hour pH-MII monitoring. If >5 reflux events were identified on pH-MII, then subjects were randomized to receive either EES or placebo. Repeat 24-hour pH-MII was performed on day 7 of study treatment and compared to initial pH-MII.

RESULTS

Forty-three premature neonates were enrolled. Of those, 31 neonates were randomized, 15 to EES and 16 to placebo with a median (IQR) pretreatment total reflux events per 24 hours of 23 (16-40) and 29 (12-40), respectively. Day 7 total events per 24 hours decreased by 4 events in the EES group to 19 (15-33) and by 10 events in the placebo group to 19 (11-26) (P = 0.09). There were no differences in pretreatment and day 7 acidic and nonacidic reflux, proximal reflux, total or percent reflux time, median or longest bolus clearance time, or nurse-reported apnea events between groups.

CONCLUSIONS

Enteral EES did not decrease reflux events on 24-hour pH-MII at the dose studied. Therefore, it may be ineffective in the treatment of GERD in premature neonates.

Postoperative ileus following major colorectal surgery

BACKGROUND

Postoperative ileus (POI) is characterized by delayed gastrointestinal recovery following surgery. Current knowledge of pathophysiology, clinical interventions and methodological challenges was reviewed to inform modern practice and future research.

METHODS

A systematic search of MEDLINE and Embase databases was performed using search terms related to ileus and colorectal surgery. All RCTs involving an intervention to prevent or reduce POI published between 1990 and 2016 were identified. Grey literature, non-full-text manuscripts, and reanalyses of previous RCTs were excluded. Eligible articles were assessed using the Cochrane tool for assessing risk of bias.

RESULTS

Of 5614 studies screened, 86 eligible articles describing 88 RCTs were identified. Current knowledge of pathophysiology acknowledges neurogenic, inflammatory and pharmacological mechanisms, but much of the evidence arises from animal studies. The most common interventions tested were chewing gum (11 trials) and early enteral feeding (11), which are safe but of unclear benefit for actively reducing POI. Others, including thoracic epidural analgesia (8), systemic lidocaine (8) and peripheral μ antagonists (5), show benefit but require further investigation for safety and cost-effectiveness.

CONCLUSION

POI is a common condition with no established definition, aetiology or treatment. According to current literature, minimally invasive surgery, protocol-driven recovery (including early feeding and opioid avoidance strategies) and measures to avoid major inflammatory events (such as anastomotic leak) offer the best chances of reducing POI.

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.

Rhubarb to Facilitate Placement of Nasojejunal Feeding Tubes in Patients in the Intensive Care Unit

BACKGROUND

Prokinetic agents are sometimes needed to aid in the placement of nasojejunal feeding tubes in patients at risk of malnutrition. The objective of the present study was to evaluate the feasibility of rhubarb as a new prokinetic agent to replace metoclopramide and erythromycin in the placement of nasojejunal feeding tubes.

MATERIALS AND METHODS

Ninety-four patients who required jejunal feeding tube insertion were included. They were divided into rhubarb (n = 34), metoclopramide (n = 31), and erythromycin groups (n = 29), depending on the use of rhubarb, metoclopramide, and erythromycin as the prokinetic agent. The jejunal feeding tube insertions were performed at the bedside. An abdominal x-ray was taken as the gold standard to determine the position of the tube. Cases in which insertion failed in either group were subjected to a second insertion attempt using rhubarb as the prokinetic agent.

RESULTS

The success rates in the rhubarb, metoclopramide, and erythromycin groups were 91.2%, 87.1%, and 89.7%, respectively. The difference in the success rates was not statistically significant (P = .916). The insertion times in the rhubarb, metoclopramide, and erythromycin groups were 16.0 ± 1.9 minutes, 18.0 ± 1.9 minutes, and 18.8 ± 2.2 minutes, respectively. The insertion time in the rhubarb group was significantly shorter than those in metoclopramide and erythromycin groups (P < .001). No side effects were noted in the rhubarb group.

CONCLUSIONS

Rhubarb could serve as an effective prokinetic agent to promote the insertion of nasojejunal feeding tubes.

Adverse effects reported in the use of gastroesophageal reflux disease treatments in children: a 10 years literature review

Gastroesophageal reflux (GER) is commonly observed in children, particularly during the first year of life. Pharmacological therapy is mostly reserved for symptomatic infants diagnosed with GER disease (GERD), usually as defined in a recent consensus statement. The purpose of the present article was to review the reported adverse effects of pharmacological agents used in the treatment of paediatric GERD. We conducted this review using the electronic journal database Pubmed and Cochrane database systematic reviews using the latest 10-year period (1 January 2003 to 31 December 2012). Our search strategy included the following keywords: omeprazole, esomeprazole, lansoprazole, pantoprazole, rabeprazole, rantidine, cimetidine, famotidine, nizatidine, domperidone, metoclopramide, betanechol, erythromycin, baclofen, alginate. We used Pubmed's own filter of: 'child: birth-18 years'. All full articles were reviewed and we only included randomized controlled trials retrieved from our search. We addressed a summary of our search on a drug-by-drug basis with regard to its mechanism of action and clinical applications, and reviewed all of the adverse effects reported and the safety profile of each drug. Adverse effects have been reported in at least 23% of patients treated with histamine H2 receptor antagonists (H2 RAs) and 34% of those treated with proton pump inhibitors (PPIs), and mostly include headaches, diarrhoea, nausea (H2 RAs and PPIs) and constipation (PPIs). Acid suppression may place immune-deficient infants and children, or those with indwelling catheters, at risk for the development of lower respiratory tract infections and nosocomial sepsis. Prokinetic agents have many adverse effects, without major benefits to support their routine use.

Emerging drugs for functional dyspepsia

INTRODUCTION

Functional dyspepsia (FD) is a relatively common gastrointestinal clinical condition that remains poorly understood. Controversies remain regarding the definition, pathophysiology and optimum treatment. The current treatment of FD is limited and no established regimen is available.

AREAS COVERED

Recent advances have improved our understanding of the pathophysiology of the disease and have led to the development of newer tailored therapies. Novel agents such as the motilin receptor agonist camicinal and the muscarinic M1 and M2 receptor antagonist acotiamide appear promising; however, the need for a safe and efficacious treatment remains largely unmet. This review describes the currently available management options for FD and critically evaluates emerging therapies.

EXPERT OPINION

The optimal treatment for FD is yet to be determined. A proton pump inhibitor or a prokinetic agent constitutes primary treatment. Helicobacter pylori testing and eradication is recommended. Based on currently available data, acotiamide appears promising, particularly in postprandial distress syndrome. Further large-scale multicentered trials are required to define the duration of treatment and the side-effect profile.

Saccharomyces boulardii ameliorates clarithromycin- and methotrexate-induced intestinal and hepatic injury in rats

Saccharomyces boulardii is a probiotic used for the prevention of antibiotic-associated diarrhoea. We aimed to investigate whether S. boulardii could alter the effects of clarithromycin (CLA) and methotrexate (MTX) on oro-caecal intestinal transit and oxidative damage in rats. Rats were divided into two groups receiving a single dose of MTX (20 mg/kg) or CLA (20 mg/kg per d) for 1 week. Groups were treated with either saline or S. boulardii (500 mg/kg) twice per d throughout the experiment. The control group was administered only saline. Following decapitation, intestinal transit and inflammation markers of glutathione (GSH), malondialdehyde and myeloperoxidase were measured in intestinal and hepatic tissues. CLA and MTX increased intestinal transit, while S. boulardii treatment slowed down CLA-facilitated transit back to control level. Both MTX and CLA increased lipid peroxidation while depleting the antioxidant GSH content in the hepatic and ileal tissues. Conversely, lipid peroxidation was depressed and GSH levels were increased in the ileal and hepatic tissues of S. boulardii-treated rats. Increased ileal neutrophil infiltration due to MTX and CLA treatments was also reduced by S. boulardii treatment. Histological analysis supported that S. boulardii protected intestinal tissues against the inflammatory effects of both agents. These findings suggest that S. boulardii ameliorates intestinal injury and the accompanying hepatic inflammation by supporting the antioxidant state of the tissues and by inhibiting the recruitment of neutrophils. Moreover, a preventive effect on MTXinduced toxicity is a novel finding of S. boulardii, proposing it as an adjunct to chemotherapy regimens.

[Perioperative protection of the gastrointestinal tract]

The gastrointestinal tract is a complex organ system. Dysfunctions of this organ system may evoke a variety of consequences for the entire organism and influence the inflammatory response in particular. In perioperative medicine, nutrition, prokinetics, peridural anesthesia, catecholamines and volume therapy can be applied in order to improve the gastrointestinal functional or at least to avoid further aggravation. Early enteral nutrition is especially important in the reduction of postsurgical ileus and infectious complications. Also, prokinetics and thoracic peridural anesthesia favorably affect postsurgical ileus. Norepinephrine, if necessary in combination with dobutamine, seems to have fewer negative effects on splanchnic perfusion than epinephrine. The data on volume therapy remain controversial but fluid balance has to be calculated very carefully also considering enteral loss of fluids. Thus, in order to treat and avoid gastrointestinal problems after surgery and to prevent negative effects for the complete organism, multimodal concepts with regard to detail are required.

The effect of erythromycin on gastrointestinal motility in subtotal gastrectomized patients

Purpose

Our objective was to determine the effect of erythromycin (EM) in improving gastrointestinal motility in subtotal gastrectomized patients. We used radio-opaque Kolomarks as an objective method. We conducted a prospective, controlled clinical trial study of 24 patients.

Methods

All patients underwent subtotal gastrectomy with 3 capsules containing Kolomarks (20 markers per 1 capsule) in the remnant stomach before anastomosis. From the day of the operation to the 2nd postoperative day, patients in the EM group began receiving 200 mg of EM intravenously for 30 minutes continuously. We counted the number of Kolomarks in the stomach, passed by stomach, in rectum, and in stool with serial simple abdominal X-ray films on the first postoperative day up to the 7th postoperative day.

Results

The study population included 14 patients in the control group and 10 patients in the EM group. The two study groups were compared in terms of their characteristics including age, gender, past medical history, cancer stage, and operation type. No significant differences were found for the demographics between the two groups. We only found a significant difference for the number of Kolomarks passed by the stomach on the 3rd postoperative day (P = 0.026).

Conclusion

Our results demonstrated that 200 mg of EM intravenous infusion during the postoperative period induced rapid gastric emptying, although it did not improve gastrointestinal motility for the entire gastrointestinal tract in subtotal gastrectomized patients.

Efficacy of intermediate-dose oral erythromycin on very low birth weight infants with feeding intolerance

BACKGROUND

Erythromycin is generally used as a prokinetic agent for the treatment of feeding intolerance in preterm infants; however, results from previous studies significantly vary due to different medication dosages, routes of administration, and therapy durations. The effectiveness and safety of intermediate-dose oral erythromycin in very low birth weight (VLBW) infants with feeding intolerance was examined in this study.

METHODS

Between November 2007 and August 2009, 45 VLBW infants with feeding intolerance, who were all at least 14 days old, were randomly allocated to a treatment group and administered 5mg/kg oral erythromycin every 6hours for 14 days (n=19). Another set of randomly selected infants was allocated to the control group, which was not administered erythromycin (n=26).

RESULTS

The number of days required to achieve full enteral feeding (36.5±7.4 vs. 54.7±23.3 days, respectively; p=0.01), the duration of parenteral nutrition (p<0.05), and the time required to achieve a body weight ≥2500g (p<0.05) were significantly shorter in the erythromycin group compared with the control group. The incidence of parenteral nutrition-associated cholestasis (PNAC) and necrotizing enterocolitis (NEC) ≥ stage II after 14 days of treatment were significantly lower (p<0.05) in the erythromycin group. No significant differences were observed in terms of the incidences of sepsis, bronchopulmonary dysplasia, or retinopathy of prematurity. No adverse effects were associated with erythromycin treatment.

CONCLUSIONS

Intermediate-dose oral erythromycin is effective and safe for the treatment of feeding intolerance in VLBW infants. The incidences of PNAC and ≥ stage II NEC were significant lower in the erythromycin group.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

The hungry stomach: physiology, disease, and drug development opportunities

During hunger, a series of high-amplitude contractions of the stomach and small intestine (phase III), which form part of a cycle of quiescence and contractions (known as the migrating motor complex, MMC), play a "housekeeping" role prior to the next meal, and may contribute toward the development of hunger. Several gastrointestinal (GI) hormones are associated with phase III MMC activity, but currently the most prominent is motilin, thought to at least partly mediate phase III contractions of the gastric MMC. Additional GI endocrine and neuronal systems play even more powerful roles in the development of hunger. In particular, the ghrelin-precursor gene is proving to have a complex physiology, giving rise to three different products: ghrelin itself, which is formed from a post-translational modification of des-acyl-ghrelin, and obestatin. The receptors acted on by des-acyl-ghrelin and by obestatin are currently unknown but both these peptides seem able to exert actions which oppose that of ghrelin, either indirectly or directly. An increased understanding of the actions of these peptides is helping to unravel a number of different eating disorders and providing opportunities for the discovery of new drugs to regulate dysfunctional gastric behaviors and appetite. To date, ghrelin and motilin receptor agonists and antagonists have been described. The most advanced are compounds which activate the ghrelin and motilin receptors which are being progressed for disorders associated with gastric hypomotility.

Effect of erythromycin before endoscopy in patients presenting with variceal bleeding: a prospective, randomized, double-blind, placebo-controlled trial

BACKGROUND

Blood in the stomach and esophagus in patients with variceal bleeding often obscures the endoscopic view and makes endoscopic intervention difficult to perform. Erythromycin, a motilin agonist, induces gastric emptying.

OBJECTIVE

To assess the effect of erythromycin on endoscopic visibility and its outcome in patients with variceal bleeding.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Tertiary care hospital.

PATIENTS

Adult patients with liver cirrhosis presenting with hematemesis within the previous 12 hours.

INTERVENTION

Either 125 mg erythromycin or placebo administered intravenously 30 minutes before endoscopy.

MAIN OUTCOME MEASUREMENTS

Endoscopic visibility during index endoscopy and mean duration of procedure. SECONDARY OUTCOME MEASUREMENTS: Need for repeat endoscopy and blood transfusions within 24 hours, endoscopy-related complications, and length of hospital stay.

RESULTS

A total of 102 patients received either erythromycin or placebo (53 erythromycin and 49 placebo). Forty-seven patients in the erythromycin group and 43 in the placebo group had variceal bleeding and were considered for final analysis. A completely empty stomach was seen in 48.9% of the erythromycin group versus 23.3% of the placebo group (P<.01). Mean endoscopy duration was significantly shorter in the erythromycin group than in the placebo group (19.0 minutes vs 26.0 minutes, respectively; P<.005). Length of hospital stay was significantly shorter in the erythromycin group than in the placebo group (3.4 days vs 5.1 days, respectively; P<.002). The need for repeat endoscopy and the mean number of units of blood transfused did not differ significantly in the 2 groups. No adverse events were observed with erythromycin.

LIMITATIONS

Sample size not sufficient to measure the need for repeat endoscopy and survival benefit.

CONCLUSIONS

Erythromycin infusion before endoscopy in patients with variceal bleeding significantly improves endoscopic visibility and shortens the duration of the index endoscopy. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01060267.).

Anesthetic Routines: The Anesthesiologist's Role in GI Recovery and Postoperative Ileus

All patients undergoing bowel resection experience postoperative ileus, a transient cessation of bowel motility that prevents effective transit of intestinal contents or tolerance of oral intake, to varying degrees. An anesthesiologist plays a critical role, not only in the initiation of surgical anesthesia, but also with the selection and transition to effective postoperative analgesia regimens. Attempts to reduce the duration of postoperative ileus have prompted the study of various preoperative, perioperative, and postoperative regimens to facilitate gastrointestinal recovery. These include modifiable variables such as epidural anesthesia and analgesia, opioid-sparing anesthesia and analgesia, fluid restriction, colloid versus crystalloid combinations, prokinetic drugs, and use of the new peripherally acting mu-opioid receptor (PAM-OR) antagonists. Review and appropriate adaptation of these multiple modifiable interventions by anesthesiologists and their surgical colleagues will facilitate implementation of a best-practice management routine for bowel resection procedures that will benefit the patient and the healthcare system.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

Gastroesophageal reflux and altered motility in lung transplant rejection

BACKGROUND

Lung transplantation has become an effective therapeutic option for selected patients with end stage lung disease. Long-term survival is limited by chronic rejection manifest as bronchiolitis obliterans syndrome (BOS). The aspiration of gastric contents has been implicated as a causative or additive factor leading to BOS. Gastroesophageal reflux (GER) and altered foregut motility are common both before and after lung transplantation. Further, the normal defense mechanisms against reflux are impaired in the allograft. Recent studies using biomarkers of aspiration have added to previous association studies to provide a growing body of evidence supporting the link between rejection and GER. Further, the addition of high-resolution manometry (HRM) and impedance technology to characterize bolus transit and the presence and extent of reflux regardless of pH might better identify at-risk patients. Although additional prospective studies are needed, fundoplication appears useful in the prevention or treatment of post-transplant BOS.

PURPOSE

This review will highlight the existing literature on the relationship of gastroesophageal reflux and altered motility to lung transplant rejection, particularly BOS. The article will conclude with a discussion of the evaluation and management of patients undergoing lung transplantation at our center.

Structure-activity relationships of 9-substituted-9-dihydroerythromycin-based motilin agonists: optimizing for potency and safety

A series of 9-dihydro-9-acetamido-N-desmethyl-N-isopropyl erythromycin A analogues and related derivatives was generated as motilin agonists. The compounds were optimized for potency while showing both minimal antibacterial activity and hERG inhibition. As the substituent on the amide was increased in lipophilicity the potency and hERG inhibition increased, while polar groups lowered potency, without significantly impacting hERG inhibition. The N-methyl acetamide 7a showed the optimal in vitro profile and was probed further by varying the chain length to the macrocycle as well as changing the macrocycle scaffold. 7a remained the compound with the best in vitro properties.

Current pharmacological management of gastro-esophageal reflux in children: an evidence-based systematic review

Gastro-esophageal reflux (GER) is a common phenomenon, characterized by the regurgitation of the gastric contents into the esophagus. Gastro-esophageal reflux disease (GERD) is the term applied when GER is associated with sequelae or faltering growth. The main aims of treatment are to alleviate symptoms, promote normal growth, and prevent complications. Medical treatments for children include (i) altering the viscosity of the feeds with alginates; (ii) altering the gastric pH with antacids, histamine H(2) receptor antagonists, and proton pump inhibitors; and (iii) altering the motility of the gut with prokinetics, such as metoclopramide and domperidone. Our aim was to systematically review the evidence base for the medical treatment of gastro-oesophageal reflux in children. We searched PubMed, AdisOnline, MEDLINE, and EMBASE, and then manually searched reviews from the past 5 years using the key words 'gastro-esophageal' (or 'gastroesophageal'), 'reflux', 'esophagitis', and 'child$' (or 'infant') and 'drug$' or 'therapy'. Articles included were in English and had an abstract. We used the levels of evidence adopted by the Centre for Evidence-Based Medicine in Oxford to assess the studies for all reported outcomes that were meaningful to clinicians making decisions about treatment. This included the impact of clinical symptoms, pH study profile, and esophageal appearance at endoscopy. Five hundred and eight articles were reviewed, of which 56 papers were original, relevant clinical trials. These were assessed further. Many of the studies considered had significant methodological flaws, although based on available evidence the following statements can be made. For infant GERD, ranitidine and omeprazole and probably lansoprazole are safe and effective medications, which promote symptomatic relief, and endoscopic and histological healing of esophagitis. Gaviscon(R) Infant sachets are safe and can improve symptoms of reflux. There is less evidence to support the use of domperidone or metoclopramide. More evidence is needed before other anti-reflux medications can be recommended. For older children, acid suppression is the mainstay of treatment. The largest evidence base supports the early use of H(2) receptor antagonists or proton pump inhibitors.

Pharmacologic Options to Prevent Postoperative Ileus

Objective:

To summarize the evidence on pharmacologic options in preventing postoperative ileus (POI).

Data Sources:

The Cochrane Database of Reviews and OVID databases and Food and Drug Administration (FDA) Web site were searched (1950–April 2009) using the term postoperative ileus.

Study Selection and Data Extraction:

Meta-analyses and randomized controlled trials were included for review. The FDA Web site was searched for clinical reviews and label information for drugs indicated for the prevention of POI.

Data Synthesis:

Three meta-analyses, 2 on gum-chewing and 1 on alvimopan, and 18 clinical trials were identified. Only gum chewing and alvimopan were effective in preventing POI. Gum chewing reduced the time to first flatus and bowel movement (weighted mean difference 21h, p = 0.0006 and 33h; p = 0.0002, respectively). In one meta-analysis, gum chewing significantly reduced length of stay (LOS) by 2.4 days (p < 0.00001) but this was not replicated in the second meta-analysis. Alvimopan shortened the time to reach a composite endpoint of solid food intake, plus/minus flatus, and bowel movement (93 vs 105 h; p < 0.001). A higher incidence of myocardial infarction was observed in a 12-month study of alvimopan for the treatment of opioid-induced bowel dysfunction, but not in studies in patients undergoing bowel resection. Alvimopan decreased the time to written hospital discharge order (hazard ratio 1.35; p<0.01), while the significance of a reduction in LOS (0.2–1.3 days) was not reported.

Conclusions:

Gum chewing and alvimopan are effective in preventing POI, but given safety concerns and higher cost with alvimopan, gum chewing may be preferred.

Inhibition of gastroesophageal reflux by semi-solid nutrients in patients with percutaneous endoscopic gastrostomy

BACKGROUND

Aspiration is one of the major complications after percutaneous endoscopic gastrostomy (PEG). The administration of semi-solid nutrients by means of gastrostomy tube has recently been reported to be effective in preventing aspiration pneumonia. The effects of semi-solid nutrients on gastroesophageal reflux, intragastric distribution, and gastric emptying were evaluated.

METHODS

Semi-solid nutrients were prepared by liquid nutrients mixed with agar at the concentration of 0.5%. The distribution of the administered radiolabeled liquid and semi-solid nutrients was monitored by a scintillation camera for 15 post-PEG patients. The percentage of esophageal reflux, the distribution of the proximal and distal stomach, and the gastric emptying time were evaluated.

RESULTS

The percentage of gastroesophageal reflux was significantly decreased in semi-solid nutrients (0.82 +/- 1.27%) compared with liquid nutrients (3.75 +/- 4.25%), whereas the gastric emptying time was not different. The distribution of semi-solid nutrients was not different from liquid nutrients in the early phase, whereas higher retention of liquid nutrients in the proximal stomach was observed in the late phase.

CONCLUSIONS

Gastroesophageal reflux was significantly inhibited by semi-solid nutrients. One of the mechanisms of the inhibition is considered to be an improvement in the transition from the proximal to distal stomach in semi-solid nutrients.

Azithromycin reduces gastroesophageal reflux and aspiration in lung transplant recipients

Azithromycin (AZI) is a macrolide antibiotic that improves lung function in lung transplant recipients (LTx). Gastroesophageal reflux (GER) has been implicated in the pathogenesis of chronic rejection after LTx. Macrolide antibiotics may affect GER by modifying esophageal and gastric motility. The purpose of this study was to evaluate the effect of AZI on GER and gastric aspiration after LTx. Acid and weakly acidic GER was measured with 24-h pH-impedance monitoring in 47 LTx patients (12 patients "on" AZI). Gastric aspiration was assessed in a separate group of 30 LTx patients before and after AZI by measurements of pepsin and bile acid in bronchoalveolar lavage fluid (BALF). Patients "on" AZI had a significant lower total number of reflux events [41 (30-61) vs. 22.5 (7-37.5)], number of acid reflux events [24 (16-41) vs. 8 (4-18)], esophageal acid exposure [2.9% (0.7-7.3) vs. 0.2% (0.1-2.0)], bolus exposure [0.73% (0.5-1.4) vs. 0.21% (0.12-0.92)], and proximal extent of reflux [14 (9-24) vs. 5 (2-7)]. AZI reduced the concentration of bile acids in BALF without affecting levels of pepsin. LTx patients "on" AZI have less GER and bile acids aspiration. This effect might be due to enhanced esophageal motility and accelerated gastric emptying.

Motilides: a long and winding road: lessons from mitemcinal (GM-611) on diabetic gastroparesis

Mitemcinal (GM-611) is a macrolide motilin receptor agonist with acid-resistance and without antibiotic activity. Since ABT-229 (a first generation of motilin receptor agonist) had failed to demonstrate symptomatic relief in functional dyspepsia and diabetic gastroparesis, there is a controversy for which of prokinetics or relaxants is clinically beneficial. Currently, oral mitemcinal has been focused on diabetic gastroparesis under clinical development. It showed to accelerate gastric-emptying in diabetic animals and in patients with gastroparesis. The latest double-blind, placebo-controlled study demonstrated to be effective at improving diabetes-related gastroparesis symptoms. A sub-group analysis, which included patients with BMI < 35 kg/m2 and hemoglobin A1c < 10%, there were significantly more symptomatic relieves in the 10 mg mitemcinal group than in the placebo group. The frequency of adverse events did not differ between groups. Mitemcinal shows promise in the subset of patients who should be confirmed in future studies.

Impact of gastrointestinal-related side effects on mycophenolate mofetil dosing and potential therapeutic strategies

In renal transplant patients receiving mycophenolate mofetil (MMF), maintaining an adequate dosing regimen has been shown to maximize short- and long-term outcomes. Gastrointestinal (GI) adverse events associated with MMF are frequent, and lead to MMF dose reduction or withdrawal in 40-50% of cases. Among MMF-treated patients experiencing GI complications, one analysis has reported MMF discontinuation to be associated with almost a threefold increase in risk of graft loss, while a dose reduction > or = 50% carried over a twofold increase in risk. If GI symptoms improve and the pre-reduction MMF dose is resumed the increased risk of graft loss may be reversed, but continuing intolerance can make this difficult to achieve. Investigation of contributing factors is important and may alleviate symptoms. Conversion to enteric-coated mycophenolate sodium (EC-MPS) may be an effective option. Two open-label studies using patient-reported outcomes data have shown a significant and clinically relevant benefit in GI-related symptom burden after conversion from MMF to EC-MPS. In conclusion, monitoring of GI complications is essential following renal transplantation, and maintaining adequate mycophenolic acid exposure should be a priority when considering treatment options.

Effects of oral mitemcinal (GM-611), erythromycin, EM-574 and cisapride on gastric emptying in conscious rhesus monkeys

We assessed and compared the effects of oral mitemcinal (an orally active, erythromycin-derived motilin-receptor agonist; Code name: GM-611), erythromycin, EM-574 and cisapride on gastric emptying in conscious Rhesus monkeys using the acetaminophen method. Mitemcinal and erythromycin induced significant, dose-dependent increases in indices of gastric emptying, but mitemcinal required a much lower dose for the same effect. Cisapride induced a bell-shaped dose response, and EM-574, a potent erythromycin derivative and originally developed as an enteric coated formulation, had little effect when it was given orally uncoated. Since our previous study showed that response to motilin is similar in Rhesus monkeys and humans, these results suggest that oral mitemcinal may be effective for the treatment of symptoms in human disorders related to delayed gastric emptying (e.g., functional dyspepsia and gastroparesis). Combined with the results of other studies, these results suggest that mitemcinal may be able to replace the withdrawn drug, cisapride, as the drug of choice for treating delayed gastric emptying.

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.

Oral mitemcinal (GM-611), an erythromycin-derived prokinetic, accelerates normal and experimentally delayed gastric emptying in conscious dogs

1. We examined effects of orally administered mitemcinal, an erythromycin-derived motilin agonist, on gastric emptying and antroduodenal motility in conscious normal dogs and conscious dogs with experimentally delayed gastric emptying. For comparison, we also examined the effects of orally administered cisapride. 2. Gastric emptying was assessed by adding paracetamol to the test meal and determining three of its pharmacokinetic parameters as indices of gastric emptying. Antroduodenal motility was assessed from the output of force transducers chronically implanted in the gastric antrum and duodenum. 3. In normal dogs, mitemcinal (0.25, 0.5 and 1 mg/kg) dose-dependently accelerated gastric emptying, significantly increasing all three indices at doses of 0.5 and 1 mg/kg; cisapride (1, 3 and 10 mg/kg) had no significant effect. Mitemcinal also dose-dependently stimulated antroduodenal motility in the interdigestive and digestive states. Cisapride, at 100-fold the dose, produced similar effects in the interdigestive state, but mixed results in the digestive state. 4. In dogs with delayed gastric emptying induced by subcutaneous clonidine (0.03 mg/kg), mitemcinal (0.25, 0.5 and 1 mg/kg) dose-dependently improved delayed gastric emptying, significantly increasing two of three indices at a dose of 1 mg/kg. Cisapride (1, 3 and 10 mg/kg) caused non-significant increases in the indices of gastric emptying, with roughly bell-shaped dose-response curves. The highest dose of mitemcinal (1 mg/kg) also stimulated antroduodenal motility. 5. In dogs with delayed gastric emptying induced by vagotomy, mitemcinal (0.125, 0.25 and 0.5 mg/kg) dose-dependently improved delayed gastric emptying, significantly increasing all three indices at doses of 0.25 and 0.5 mg/kg. Cisapride (3 mg/kg) restored the indices to roughly prevagotomy levels, but none of the increases was significant. Mitemcinal, at a dose of 0.25 mg/kg, also stimulated antroduodenal motility. 6. Because delayed gastric emptying is the basic characteristic of gastroparesis, the fact that mitemcinal accelerated gastric emptying in dogs with normal and delayed gastric emptying much more robustly than cisapride adds to the evidence that mitemcinal is likely to be useful for the treatment of patients with gastroparesis.

Systemic prokinetic pharmacologic treatment for postoperative adynamic ileus following abdominal surgery in adults

BACKGROUND

Postoperative adynamic bowel atony interferes with recovery following abdominal surgery. Prokinetic pharmacologic drugs are widely used to accelerate postoperative recovery.

OBJECTIVES

To evaluate the benefits and harms of systemic acting prokinetic drugs to treat postoperative adynamic ileus in patients undergoing abdominal surgery.

SEARCH STRATEGY

Trials were identified by computerised searches of the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and the Cochrane Colorectal Cancer Group specialised register. The reference lists of included trials and review articles were tracked and authors contacted.

SELECTION CRITERIA

Randomised controlled parallel-group trials (RCT) comparing the effect of systemically acting prokinetic drugs against placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Four reviewers independently extracted the data and assessed trial quality. Trial authors were contacted for additional information if needed.

MAIN RESULTS

Thirty-nine RCTs met the inclusion criteria contributing a total of 4615 participants. Most trials enrolled a small number of patients and showed moderate to poor (reporting of) methodological quality, in particular regarding allocation concealment and intention-to-treat analysis. Fifteen systemic acting prokinetic drugs were investigated and ten comparisons could be summarized. Six RCTs support the effect of Alvimopan, a novel peripheral mu receptor antagonist. However, the trials do not meet reporting guidelines and the drug is still in an investigational stage. Erythromycin showed homogenous and consistent absence of effect across all included trials and outcomes. The evidence is insufficient to recommend the use of cholecystokinin-like drugs, cisapride, dopamine-antagonists, propranolol or vasopressin. Effects are either inconsistent across outcomes, or trials are too small and often of poor methodological quality. Cisapride has been withdrawn from the market due to adverse cardiac events in many countries. Intravenous lidocaine and neostigmine might show a potential effect, but more evidence on clinically relevant outcomes is needed. Heterogeneity among included trials was seen in 10 comparisons. No major adverse drug effects were evident.

AUTHORS' CONCLUSIONS

Alvimopan may prove to be beneficial but proper judgement needs adherence to reporting standards. Further trials are needed on intravenous lidocaine and neostigmine. The remaining drugs can not be recommended due to lack of evidence or absence of effect.