Review article: promotility drugs in the treatment of gastro-oesophageal reflux disease

Efficacy comparison between oral erythromycin versus domperidone for the treatment of feeding intolerance in preterm neonates

BACKGROUND

Domperidone and erythromycin are commonly used as prokinetic agents for feeding intolerance in preterm neonates; however, no data from a previous study have compared their efficacy. This study aimed to compare the efficacy of orally administered domperidone and erythromycin for the treatment of feeding intolerance in preterm infants.

METHODS

This retrospective cohort study included preterm neonates with a birthweight of <1800 g and gestational age <37 weeks. Data were collected from medical records at Queen Sirikit National Institute of Child Health (QSNICH) from 2006 to 2014. The primary outcome was the time to establish full enteral feeding (150 ml/kg/day) after starting oral domperidone or erythromycin for the treatment of feeding intolerance in preterm neonates. The secondary outcome was adverse effects associated with domperidone and erythromycin therapy.

RESULTS

Among the 150 preterm neonates enrolled in this study, 66 received domperidone, and 84 received erythromycin. The baseline characteristics and comorbidities were not significantly different between the two groups; however, the gestational age at birth of neonates in the domperidone group was significantly lower than that of those in the erythromycin group. The time to establish full enteral feeding did not differ between the domperidone (11 days, "IQR," [6, 17]) and erythromycin (10 days, IQR [7, 14]) groups (p = 0.622). No major adverse effects were noted. There were only three preterm infants who had elevated liver enzymes in each group, but the difference between groups was not significant.

CONCLUSION

From this study, the efficacy of oral domperidone was promising equivalent to oral erythromycin and seems to be one of the treatment options for feeding intolerance in preterm neonates. However, large randomized, controlled trials are needed to confirm the efficacy and safety of domperidone in this population.

Management of Ineffective Esophageal Hypomotility

Esophageal hypomotility in general and especially ineffective esophageal motility according to the Chicago criteria of primary motility disorders of the esophagus, is one of the most frequently diagnosed motility disorders on high resolution manometry and results in a large number of patients visiting gastroenterologists. Most patients with esophageal hypomotility present with gastroesophageal reflux symptoms or dysphagia. The clinical relevance of the motility pattern, however, is not well established but seems to be correlated with disease severity in reflux patients. The correlation with dysphagia is less clear. Prokinetic agents are commonly prescribed as first line pharmacologic intervention to target esophageal smooth muscle contractility and improve esophageal motor functions. However, the beneficial effects of these medications are limited and only confined to some specific drugs. Serotonergic agents, including buspirone, mosapride and prucalopride have been shown to improve parameters of esophageal motility although the effect on symptoms is less clear. Understanding on the complex correlation between esophageal hypomotility and esophageal symptoms as well as the limited evidence of prokinetic agents is necessary for physicians to appropriately manage patients with Ineffective Esophageal Motility (IEM).

Pathophysiology and treatment options for gastroesophageal reflux disease: looking beyond acid

Gastroesophageal reflux disease (GERD) is a disorder due to the retrograde flow of refluxate into the esophagus. Although GERD is a common clinical diagnosis, its pathogenesis is quite complex. As a result of its multifactorial development, many patients continue to experience adverse symptoms due to GERD despite prolonged acid suppression with proton pump inhibitor therapy. The pathogenesis of GERD involves an interplay of chemical, mechanical, psychologic, and neurologic mechanisms, which contribute to symptom presentation, diagnosis, and treatment. As such, GERD should be approached as a disorder beyond acid. This review will investigate the major factors that contribute to the development of GERD, including factors related to the refluxate, esophageal defenses, and factors that promote pathologic reflux into the esophagus. In reviewing GERD pathogenesis, this paper will highlight therapeutic advances, with mention of future opportunities of study when approaching GERD.

Effect of metoclopramide on nausea and emesis in dogs premedicated with morphine and dexmedetomidine

OBJECTIVE

To evaluate whether subcutaneous (SC) metoclopramide (0.2 mg kg^-1) administered 30 minutes prior to (T30) or simultaneously with (T0) intramuscular (IM) morphine (0.2 mg kg^-1) and dexmedetomidine (0.003 mg kg^-1) reduces the incidence of nausea and emesis in healthy dogs.

STUDY DESIGN

Prospective, randomized and blinded study.

ANIMALS

A total of 45 dogs scheduled for elective procedures.

METHODS

Dogs were assigned randomly to three groups to be administered SC metoclopramide (0.2 mg kg^-1) 30 minutes before (group M30) or simultaneously (group M0) to IM morphine (0.2 mg kg^-1) and dexmedetomidine (0.003 mg kg^-1). Dogs in the control group (group C) were administered SC saline at T30 and T0. Dogs were observed for 30 minutes after premedication to evaluate signs of nausea (continuous lip-licking and sialorrhoea) and emesis. Signs of pain or discomfort caused by SC injections were also recorded.

RESULTS

There were no statistical differences amongst groups for age, body weight and sex. More dogs developed continuous lip-licking in group C (12/15, 80.0%) compared to dogs in group M30 (1/15, 6.7%) and dogs in group M0 (5/15, 33.3%; p = 0.0001 and p = 0.01, respectively). More dogs developed sialorrhoea in group M0 (8/15, 53.3%) and in group C (10/15, 66.7%) compared to dogs in group M30 (2/15, 13.3%; p = 0.03 and p = 0.004, respectively). More dogs vomited in group M0 (4/15, 26.7%) and in group C (9/15, 60.0%) compared to dogs in group M30 (0/15, 0.0%; p = 0.05 and p = 0.0003, respectively). None of the dogs demonstrated signs of pain or discomfort during SC metoclopramide injection.

CONCLUSIONS AND CLINICAL RELEVANCE

Subcutaneous metoclopramide at 0.2 mg kg^-1 may reduce IM morphine and dexmedetomidine-induced nausea and emesis if administered 30 minutes in advance. It is effective in reducing lip-licking even when administered concurrently with IM morphine-dexmedetomidine.

Gastric Function in Children with Oesophageal Atresia and Tracheoesophageal Fistula

Oesophageal atresia and tracheoesophageal fistula (OA-TOF) are a multifaceted condition which affects patients throughout their lives. Even though it is one of the most common gastrointestinal malformations, most of the current studies focus on gastro-oesophageal reflux disease, anastomotic strictures, and feeding difficulties. However, there is increasing evidence that a proportion of patients with OA-TOF also have abnormal gastric function. This review aims to provide a comprehensive understanding of studies of gastric function in patients with OA-TOF. The etiology of this abnormality has been hypothesized to be congenital and/or acquired. Several modalities are currently available for the investigation of gastric function, each of them trying to answer specific clinical questions. This review summarizes the studies that have looked at gastric function in the OA-TOF cohort with gastric emptying studies (gastric emptying scintigraphy and ¹³C octanoic breath test), gastric manometry, electrogastrography, and oral glucose tolerance test. However, these modalities are limited due to poor age-specific normative values and heterogeneous methodologies used. The evaluation of symptoms in this cohort is crucial, modalities for abnormal gastric function are also described. With appropriate investigations and symptoms questionnaires, treatment strategies can be implemented to correct abnormal gastric function and thereby improve the outcomes and quality of life of patients with OA-TOF. This review highlights the need for large international multicentre collaborative studies and high-quality prospective randomized controlled trials to improve our understanding of gastric function in this cohort.

Effect of orally administered cisapride, bethanechol, and erythromycin on the apparent efficiency of colostral IgG absorption in neonatal Holstein-Friesian calves

Objective

To evaluate the effect of orally administered cisapride, bethanechol, and erythromycin on the absorption of colostral IgG in dairy calves.

Animals

Twenty‐four healthy neonatal Holstein‐Friesian calves.

Procedures

Calves were randomly assigned to one of the following treatments: 0.9% NaCl solution (2 mL, PO; negative control); erythromycin lactobionate (20 mg/kg BW, PO; anticipated to be a positive control); cisapride (0.5 mg/kg BW, PO); bethanechol chloride (0.5 mg/kg BW, PO). Calves were fed 3 L of pooled bovine colostrum containing acetaminophen (50 mg/kg) by suckling and oroesophageal intubation 30 minutes after each treatment was administered. Jugular venous blood samples were obtained periodically after the start of feeding and plasma total IgG, protein, acetaminophen, and glucose concentrations determined. Abomasal emptying rate was assessed by the time to maximal plasma acetaminophen concentration.

Results

Oral administration of cisapride facilitated the absorption of colostral IgG and protein. The effect of cisapride on abomasal emptying rate could not be evaluated because cisapride appeared to interfere with acetaminophen metabolism. Based on the total IgG and total protein concentration‐time relationships, the beneficial effects of cisapride appeared to occur early after oral administration and were transient.

Conclusions and Clinical Importance

Additional studies appear indicated to characterize the effect of cisapride dose on the magnitude and duration of its effect on facilitating the absorption of colostral IgG and protein. Identification of a nonantimicrobial method for increasing abomasal emptying rate, such as cisapride, will potentially provide a practical and effective method for facilitating transfer of passive immunity in colostrum‐fed dairy calves.

Gastroesophageal reflux in patients treated for congenital diaphragmatic hernia: short- and long-term evaluation with multichannel intraluminal impedance

PURPOSE

The incidence of GER, related symptoms and complications in patients treated for congenital diaphragmatic hernia (CDH) are poorly defined. The aim was to evaluate incidence and development of GER in children treated for CDH in a short- and long-term follow-up period, identifying potential risk factors of morbidity.

METHODS

Thirty-six patients were evaluated with pH-MII at a median age of 6 months (T1) and re-evaluated with pH-MII and endoscopy at a median age of 5 years (T2).

RESULTS

The incidence of reflux was 83 % in T1 and 61 % in T2; the incidence of symptoms was 62 % in T1 and 38 % in T2. In both groups the reflux was mainly non-acidic. Patch, intrathoracic stomach and esophageal dysmotility were risk factors for GER.

CONCLUSIONS

The incidence of GER and symptoms decrease over the time but it was higher than in the literature, probably because it is mainly non-acidic and evaluable only with MII. The esophageal dysmotility was found to be the main risk factor. An high incidence of reflux and esophagitis was found also in asymptomatic patients, and so a close follow-up is recommended in all patients even if it is asymptomatic.

Randomised clinical trial: efficacy of the addition of a prokinetic, mosapride citrate, to omeprazole in the treatment of patients with non-erosive reflux disease - a double-blind, placebo-controlled study

BACKGROUND

Proton pump inhibitors (PPIs) are less effective in non-erosive reflux disease (NERD) patients than in reflux oesophagitis patients. Whether the addition of prokinetics to PPIs improves NERD patients' symptoms remains unknown.

AIM

To evaluate the efficacy of mosapride in NERD patients when used with PPI.

METHODS

A total of 200 NERD patients were randomised to one of two arms: omeprazole (10 mg once daily) plus mosapride citrate (5 mg three times a day) (treatment arm) and omeprazole plus placebo (placebo arm). The primary endpoint was the rate of responders [visual analogue scale (VAS) was zero or <1 cm] after 4 weeks of treatment. The secondary endpoints were changes in the VAS score and the safety profile.

RESULTS

There was no significant difference between the rates of responders in both arms in intent-to-treat (ITT) and per-protocol (PP) analysis. The change in the VAS score in treatment arm was significantly better than placebo arm in PP analysis (-4.0 ± 0.2 and -3.3 ± 0.2, mean ± S.E.M.) (N.S. in ITT analysis). The rate of adverse events was similar in both groups.

CONCLUSION

The addition of mosapride to omeprazole was not more effective than omeprazole alone.

The effects of itopride on oesophageal motility and lower oesophageal sphincter function in man

BACKGROUND

Itopride is a new prokinetic agent that combines antidopaminergic and cholinesterase inhibitory actions. Previous studies suggested that itopride improves heartburn in functional dyspepsia, and decreases oesophageal acid exposure in gastro-oesophageal reflux disease. It remains unclear whether this effect is due to effects of itopride on the lower oesophageal sphincter (LES).

AIMS

To study the effects of itopride on fasting and postprandial LES function in healthy subjects.

METHODS

Twelve healthy volunteers (five men; 32.6 ± 2.0 years) underwent three oesophageal sleeve manometry studies after 3 days premedication with itopride 50 mg, itopride 100 mg or placebo t.d.s. Drug was administered after 30 min and a standardized meal was administered after 90 min, with measurements continuing to 120 min postprandially. Throughout the study, 10 wet swallows were administered at 30-min intervals, and gastrointestinal symptoms were scored on 100 mm visual analogue scales at 15-min intervals.

RESULTS

Lower oesophageal sphincter resting pressures, swallow-induced relaxations and the amplitude or duration of peristaltic contractions were not altered by both doses of itopride, at all time points. Itopride pre-treatment inhibited the meal-induced rise of transient LES relaxations (TLESRs).

CONCLUSIONS

Itopride inhibits TLESRs without significantly affecting oesophageal peristaltic function or LES pressure. These observations support further studies with itopride in gastro-oesophageal reflux disease.

Increased colonic transit in rats produced by a combination of a cholinesterase inhibitor with a 5-HT4 receptor agonist

Increased cholinergic stimulation and accelerated gastrointestinal (GI) transit may be produced by direct stimulation of the acetylcholine (ACh) receptor with an appropriate agonist by increased release of ACh from cholinergic nerve terminals or by a decreased removal or breakdown of ACh within cholinergic synapses. The acetylcholinesterase inhibitor, neostigmine, and the 5-HT(4) receptor partial agonist tegaserod, are two agents with known prokinetic activity which work by different mechanisms that result in increased levels of ACh at cholinergic synapses innervating intestinal smooth muscle. Here, we aimed to investigate the potential synergistic effect on colonic transit that may occur with concomitant use of these two agents. Colonic transit was indirectly assessed in rats via measurements of fecal pellet output every 30 min for 2.5 h following administration of neostigmine (0.003-0.1 mg kg(-1), i.p.), tegaserod (0.01-1.0 mg kg(-1), i.p.), or a combination of both compounds. When administered alone, neostigmine or tegaserod caused a dose-dependent increase in fecal pellet output. In combination, low doses of the two agents which did not produce statistically significant effects alone, compared to the vehicle, caused a significant increase in fecal pellet output. Combinations of higher doses of neostigmine and tegaserod did not display synergy. In summary, when combined at low doses, neostigmine and tegaserod produce synergistic effects manifested by a statistically significant increase in the expulsion of fecal pellets. A combination of an anticholinesterase agent with a 5-HT(4) receptor agonist may prove to be a useful therapeutic approach to treat conditions associated with slow GI transit.

Short-term effect of domperidone on gastroesophageal reflux in newborns assessed by combined intraluminal impedance and pH monitoring

OBJECTIVE

Neonatal gastroesophageal reflux (GER) is primarily due to a transient motility disorder and characterized by a prevalence of weakly acid refluxes. Drug management, where necessary, must set out to reduce the number of refluxes besides correct their acidity. Prokinetics could be of assistance in this respect, though the evidence in favor of their efficacy and safety is still far from sufficient. In this randomized controlled study, the action of domperidone, a prokinetic antidopaminergic drug with little effect on the central nervous system, was evaluated in newborns with symptomatic GER.

STUDY DESIGN

Combined multichannel intraluminal impedance and pH measuring for 24 h was carried out in 13 newborns receiving 0.3 mg per kg domperidone per os at the eighth and the sixteenth hour, and 13 controls. Each newborn was compared to the control nearest in postconceptional age.

RESULT

GER episodes per hour increased significantly compared to the baseline in the domperidone group (4.06+/-1.16 vs 2.8+/-1.42; P=0.001) and were shorter (16.68+/-4.49 vs 20.18+/-7.83 s; P=0.043), whereas there were no differences in the maximum proximal extent reached by the refluxes (3.37+/-0.45 vs 3.34+/-0.94 channels; P=0.894) and their pH (4.72+/-0.69 vs 4.60+/-1.17; P=0.634).

CONCLUSION

This paradoxical increase in the number of GER episodes could be the expression of a domperidone-induced amplification of the motor incoordination of the neonatal gastroesophageal tract. Doubt is thus cast on the efficacy of prokinetics in this age bracket, especially in view of their adverse effects as described in the literature.

Population pharmacokinetics of domperidone in preterm neonates

PURPOSE

A population pharmacokinetic analysis was performed to define domperidone pharmacokinetic parameters in preterm neonates, as no pharmacokinetic data are available in this population.

METHODS

An oral domperidone solution was administered (0.75 mg/kg per day) in 32 preterm neonates (64 samples). Domperidone plasma concentration was measured by high-performance liquid chromatography (HPLC) assay, and a one-compartment model with first-order absorption was fitted to the data using NONMEM version V level 1.1.

RESULTS

The mean peak and trough plasma concentration values of domperidone were, respectively, 25.3 +/- 20.5 ng/ml and 15.4 +/- 11.4 ng/ml (mean +/- standard deviation). The pharmacokinetic parameters (interindividual variability%) were clearance (Cl/F) = 0.92 L/h (51.6%), volume of distribution (Vd/F) = 0.405 L (68%), and absorption constant rate (Ka) = 0.0843 h(-1) (55.8%). The clearance is not lower than values reported in adults. No influence of covariates (postnatal age, prematurity, weight, gender) on domperidone pharmacokinetic parameters was found.

CONCLUSION

This pilot study designed with a limited sampling strategy showed that domperidone plasma concentrations were consistent with those reported in adults, suggesting that domperidone dosage regimen currently used in preterm neonates is suitable.

Long-term azithromycin for bronchiolitis obliterans syndrome after lung transplantation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is a major cause of morbidity and mortality after lung transplantation (LTx). Macrolides are a promising treatment option for BOS. The objective of this study was to determine long-term results of azithromycin treatment in patients with BOS. Variables to predict treatment response were evaluated.

METHODS

An observational study in a single center was performed. Eighty-one adult LTx-recipients (single, double, combined, and re-do) with at least BOS stage 0p (mean forced expired volume in 1 second [FEV1] 55+/-19%) were included. For treatment, 250 mg of oral azithromycin was administered three times per week.

RESULTS

Twenty-four of 81 (30%) patients showed improvement in FEV1 after 6 months, 22/24 already after 3 months of treatment. By univariate analysis, responders at 6 months had higher pretreatment bronchoalveolar lavage (BAL) neutrophils (51+/-29 vs. 21+/-24%). A cutoff value of <20% in pretreatment BAL had a negative predictive value of 0.91 for treatment response. Thirty-three patients (40%) showed disease progression during follow-up (491+/-165 days). Cox regression analysis identified a rapid pretreatment decline in FEV1 and comedication of an mammalian target of rapamycin inhibitor as positive predictors and proton pump inhibitor comedication and a treatment response at 3 months as negative predictors for disease progression (FEV1<90% baseline).

CONCLUSIONS

Azithromycin can improve airflow limitation in a significant proportion of patients with even long-standing BOS. The majority of responders were identified after 3 months of treatment. Results indicate the predictive value of BAL neutrophilia for treatment response and pretreatment course of FEV1 as a variable for disease progression. Beneficial effects on gastroesophageal reflux disease may be a mechanism of action.

Bethanechol improves smooth muscle function in patients with severe ineffective esophageal motility

BACKGROUND

There is no therapeutic intervention that reliably restores smooth muscle contractility for patients with ineffective esophageal motility (IEM). Bethanechol, a direct-acting muscarinic receptor agonist, has been shown in healthy volunteers to produce a significant increase in peristaltic amplitude in the distal esophagus.

AIM

To identify whether bethanechol improves smooth muscle contractility and bolus transit in patients with IEM.

METHODS

Seven patients diagnosed with severe IEM documented by combined multichannel intraluminal impedance and esophageal manometry were asked to participate. IEM was defined by using the new proposed criteria of greater than or equal to 50% saline swallows with contraction amplitude <30 mm Hg either 5 and/or 10 cm above the lower esophageal sphincter (LES). In the supine position, the patients were given 10 swallows of 5 mL of normal saline then 10 swallows of viscous solution, each 20 to 30 seconds apart. Patients were then given 50 mg oral bethanechol. After 20 and 40 minutes, 5 swallows of saline and viscous solution were repeated. Studies were then analyzed by an investigator blinded to the relationship of bethanechol administration to the swallows. The analysis included measurement of distal esophageal amplitude (DEA) or the mean amplitude at 5 and 10 cm above the LES.

RESULTS

The use of bethanechol significantly increased (P<0.05) the esophageal contraction pressures at 5 and 10 cm above the LES. The DEA increased (P<0.05) for liquid and viscous, 20 minutes after its administration. Forty minutes after bethanechol administration, DEA and also individual pressures at 5 and 10 cm above the LES were still increased (P<0.05) for liquid, but only the DEA increased (P<0.05) with viscous solution. There was also a significant increase in complete bolus transit for saline swallows, both 20 and 40 minutes (P=0.03 and 0.01, respectively) after bethanechol.

CONCLUSIONS

Oral bethanechol significantly improves contraction pressures and bolus transit in the smooth muscle portion of the esophagus in patients with severe IEM.

The use of erythromycin as a gastrointestinal prokinetic agent in adult critical care: benefits versus risks

Erythromycin A, the first macrolide, was introduced in the 1950s and after years of clinical experience it still remains a commonly relied upon antibiotic. In the past, pharmacodynamic characteristics of macrolides beyond antimicrobial action such as anti-inflammatory and immune-modulating properties have been of scientific and clinical interest. The function of erythromycin as a prokinetic agent has also been investigated for a range of gastrointestinal motility disorders and more recently within the context of critically ill patients. Prokinetic agents are drugs that increase contractile force and accelerate intraluminal transit. Whilst the anti-inflammatory action may be a desirable side effect to its antibiotic action, using erythromycin A merely for its prokinetic effect alone raises the concern about promoting emergence of macrolide resistance. The objectives of this review article are: (i) to briefly summarize the modes and epidemiology of macrolide resistance, particularly in respect to that found in the Streptococcus species (a potential reservoir for the dissemination of macrolide resistance on the critical care unit); (ii) to discuss in this context the evidence for conditions promoting bacterial resistance against macrolides; and (iii) to assess the potential clinical benefit of using erythromycin A as a prokinetic versus the risks of promoting emergence of macrolide resistance in the clinical setting. We conclude, that in view of the growing weight of evidence demonstrating the potential epidemiological impact of the increased use of macrolides upon the spread of resistance, versus a lack of sufficient and convincing evidence that erythromycin A is a superior prokinetic agent to potential alternatives in the critically ill patient population, at this stage we do not advocate the use of erythromycin A as a prokinetic agent in critically ill patients unless they have failed all other treatment for impaired gastrointestinal dysmotility and are intolerant of metoclopramide. Further large and methodologically robust studies are needed to ascertain the effectiveness of erythromycin A and other alternative agents in the critically ill.

Effect of an acute intraluminal administration of capsaicin on oesophageal motor pattern in GORD patients with ineffective oesophageal motility

Ineffective oesophageal motility (IOM) is a functional disorder affecting about 50% of gastro-oesophageal reflux disease (GORD) patients. This disease in a severe form limits the clearing ability of the oesophagus and is considered one of the predictive factors for poorer GORD resolution. Capsaicin, the active compound of red pepper, exerts a prokinetic effect on oesophageal motility in healthy subjects by increasing the amplitude of body waves, even if no evidence exists on its possible role in situations of reduced motility. The aim of the study was to evaluate the effect of an acute administration of capsaicin on the oesophageal motor pattern in a group of GORD patients affected by severe IOM. Twelve GORD patients with severe IOM received an intra-oesophageal administration of 2 mL of a red pepper-olive oil mixture and 2 mL of olive oil alone serving as a control during a stationary manometry. The motor patterns of the oesophageal body and lower oesophageal sphincter (LOS) were analysed at baseline and after the infusion of the two stimuli. The administration of capsaicin induced a significant improvement in oesophageal body contractility when compared with baseline. The velocity of propagation of waves and the LOS basal tone remained unchanged. The motor pattern was unaltered by the administration of olive oil alone. An acute administration of capsaicin seems to improve the motor performance of the oesophageal body in patients with ineffective motility. Whether this could represent the basis for further therapeutic approaches of GORD patients needs further study.

Gastroesophageal reflux

Gastroesophageal reflux disease (GERD) is the most common disease of the gastrointestinal system. Heartburn, regurgitation, and dysphagia are the most common symptoms of GERD. However, chest pain, chronic cough, laryngitis, hoarseness, and other otolaryngologic manifestation can be the primary manifestations of the disease. Endoscopy, barium studies, and especially pH monitoring and therapeutic trials may help in establishing the diagnosis of GERD. The introduction of H2 antagonists and especially of proton pump inhibitors (PPI) has brought symptomatic relief in most patients. However, surgical procedures, especially laparoscopic fundoplication, are still required in some patients. Barrett's esophagitis is the most common complication of GERD and is associated with a high prevalence of esophageal adenocarcinoma. Whether or not treatment with either PPIs or H2 antagonists can prevent this complication is still under investigation.

Management of esophageal symptoms following fundoplication

Laparoscopic antireflux surgery has emerged as a widely used and effective management option for the properly selected patient with gastroesophageal reflux disease. Poor symptomatic outcomes occur even in the best of hands, the most common being recurrent or persistent heartburn (or atypical symptoms) and dysphagia. When heartburn predominates, the initial management step is an anatomical and physiologic evaluation to determine whether acid reflux is controlled and if the postoperative neoanatomy is appropriate. If anatomical evaluation indicates surgical failure (eg, slipped or loose fundoplication, recurrent hiatal hernia), earlier re- operation may be warranted. Objective evidence of ongoing acid reflux or a reflux-symptom association despite anatomical integrity indicates reintroduction of antireflux medical therapy. Evidence favoring physiologic and anatomical success should direct treatment toward functional heartburn, including the use of tricyclic antidepressants. Dysphagia in the immediate postoperative setting mandates reassurance, as conservative measures alone often suffice while postoperative changes resolve. With persistent dysphagia, anatomical and physiologic evaluation is again indicated in the search for a mechanical-, motility-, or reflux-related symptom basis. Dilation techniques can prevent the need for re-operation, but persistent dysphagia associated with distorted postoperative anatomy will likely require surgical intervention. Regardless of the indication, re-operation carries substantial morbidity and reduced success rates compared with the initial procedure. These procedures mandate careful patient selection and referral to a center with thorough surgical experience.

Effect of itopride, a new prokinetic, in patients with mild GERD: A pilot study

AIM: Itopride is a newly developed prokinetic agent, which enhances gastric motility through both antidopaminergic and anti-acetylcholinesterasic actions. The importance of esophageal motor dysfunction in the pathogenesis of gastro-esophageal reflux disease (GERD) makes it interesting to examine the effect of itopride on esophageal acid exposure.

METHODS: The effect of itopride on esophageal acid reflux variables for 24 h was studied in 26 patients with GERD symptoms, pre-entry total acid exposure time (pH<4) of more than 5% and mild esophagitis (Savary-Miller grades I, II) proven by endoscopy. Ambulatory 24-h pH-metry and symptom assessment were performed after treatments with 150 or 300 mg itopride thrice a day (t.i. d.) for 30 d in random order, using an open label method. For evaluating the safety of itopride, blood biochemical laboratory test was performed and the serum prolactin level was also examined before and after treatment.

RESULTS: Total symptom score was significantly decreased after treatment in 150- or 300-mg group. Itopride 300 mg was significantly effective than 150 mg on decreasing the total per cent time with pH < 4, total time with pH < 4 and DeMeester score. No serious adverse effects were observed with administration of itopride in both groups.

CONCLUSION: Itopride 100 mg t.i.d. is effective on decreasing pathologic reflux in patient with GERD and therefore it has the potential to be effective in the treatment of this disease.

Management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a chronic condition requiring long-term treatment. Simple lifestyle modifications are the first methods employed by patients and, because of their low cost and simplicity, should be continued even when more potent therapies are initiated. Potent acid-suppressive therapy is currently the most important and successful medical therapy. Whereas healing of the esophageal mucosa is achieved with a single dose of any proton pump inhibitor (PPI) in more than 80% of cases, symptoms are more difficult to control. Patients with persistent symptoms on therapy should be tested (preferably with combined multichannel intraluminal impedance and pH) for association of symptoms with acid, nonacid, or no GER. Long-term follow-up studies indicate that PPIs are efficacious, tolerable, and safe medication. So far, promotility agents have shown limited efficacy, and their side-effect profile outweighs their benefits. Antireflux surgery in carefully selected patients (ie, young, typical GERD symptoms, abnormal pH study, and good response to PPI) is as effective as PPI therapy and should be offered to these patients as an alternative to medication. Still, patients should be informed about the risks of antireflux surgery (ie, risk of postoperative dysphagia; decreased ability to belch, possibly leading to bloating; increased flatulence). Endoscopic antireflux procedures are recommended only in selected patients and given the relative short experience with these techniques, patients treated with endoscopic procedures should be enrolled in a rigorous follow-up program.

Medical management of nocturnal symptoms of gastro-oesophageal reflux disease in the elderly

Elderly patients with nocturnal symptoms of gastro-oesophageal reflux disease (GORD) usually experience a more aggressive and complicated disease course compared with younger patients, resulting in impaired quality of life. The severity of disease and possible complications should be evaluated with upper endoscopy once the diagnosis is suspected. Elderly patients with nocturnal symptoms of GORD and evidence of endoscopic complications (oesophagitis, Barrett's oesophagus, etc.) and those with severe endoscopically negative reflux disease (ENRD) should be treated with proton pump inhibitors. Histamine H(2) receptor antagonists are suitable for mild-to-moderate ENRD. Antacids and lifestyle modifications may be incorporated into the management as adjuncts to more potent and durable therapeutic agents. Effective treatment of nocturnal GORD symptoms in the elderly will result in relief of symptoms, healing of oesophagitis and improved quality of life, and should be maintained indefinitely to prevent relapses of the disease.

The impact of treatment for gastro-oesophageal reflux disease on health-related quality of life: a literature review

Gastro-oesophageal reflux disease (GORD) is common in the general population and is diagnosed based on patient-reported symptoms and clinical tests. Although clinical tests are available, significant percentages of patients report symptoms of heartburn and reflux despite negative endoscopies, and 24-hour pH tests are not often used by primary-care physicians in diagnosis. Consequently, patient-reported symptoms and health-related QOL (HR-QOL) are important in assessing treatment outcome. HR-QOL is significantly impaired in patients with GORD, and HR-QOL is associated with symptom severity and changes in GORD-related symptoms. The objective of this literature review is to examine the impact of pharmacological treatment on HR-QOL in patients with GORD. Generic and disease-specific HR-QOL measures have been used in clinical trials to evaluate the impact of GORD on patient functioning and well-being. The Psychological General Well-Being (PGWB) Index and the 36-Item Short-Form Health Survey (SF-36) have been used in several clinical trials of treatment for GORD and have consistently shown that HR-QOL improves with successful therapy. These trials have been conducted primarily with two pharmacological agents, omeprazole and ranitidine. On the Heartburn-specific Quality of Life questionnaire, patients treated with ranitidine reported better HR-QOL after treatment compared with placebo therapy. In two clinical trials where omeprazole and ranitidine were compared, patients treated with omeprazole reported significantly better HR-QOL (based on the PGWB Index) than those treated with ranitidine; however, 2 other trials did not detect significant differences between the treatments. Results from clinical trials using disease-specific measures (Gastrointestinal Quality of Life Index [GIQLI] and Heartburn-specific Quality of Life questionnaire) demonstrate similar findings, supporting the association between treatment-related symptom resolution and improvements in HR-QOL. The GIQLI was used in a trial comparing pantoprazole and ranitidine, where results favoured pantoprazole therapy. Several studies have demonstrated that resolution of GORD symptoms is associated with improvement in HR-QOL. Although there is evidence that treatment for GORD does improve symptoms and HR-QOL outcomes, further research is needed to more completely understand the value of medical therapy for GORD.

Treatment of gastroesophageal reflux disease

Therapeutic modalities for gastroesophageal reflux disease (GERD) continue to evolve despite the introduction of proton pump inhibitors (PPIs), the most successful antireflux class of drugs. On-demand modalities such as antacids and alginates as well as histamine type-2 receptor antagonists continue to be popular with GERD patients who seek temporary relief of symptoms. The PPIs have revolutionized the treatment of patients with severe erosive esophagitis, complications of GERD, and atypical or extraesophageal manifestations of GERD. Antireflux surgery, commonly performed via laparoscopy, remains popular among patients who do not wish to take medications long term. In addition, the recent introduction of various endoscopic techniques offers GERD patients a long-term solution with less morbidity and lower cost than antireflux surgery.

Pharmacology for the gastrointestinal tract

A variety of drugs are used in the neonatal nursery for the management of feeding intolerance, gastroesophageal reflux, and acid-related disease. Although the pharmacokinetics of some of these drugs have been described in infants and older children, further data are needed, particularly for preterm infants. No data are available characterizing the disposition of the proton pump inhibitors, which will likely be used in infants with refractory, acid-related disease. Further data are also needed to characterize fully the pharmacodynamics, or efficacy, of many of the commonly used drugs.

Enteral feeding: drug/nutrient interaction

Enteral nutrition support via a feeding tube is the first choice for artificial nutrition. Most patients also require simultaneous drug therapy, with the potential risk for drug-nutrient interactions which may become relevant in clinical practice. During enteral nutrition, drug-nutrient interactions are more likely to occur than in patients fed orally. However, there is a lack of awareness about its clinical significance, which should be recognised and prevented in order to optimise nutritional and pharmacological therapeutic goals of safety and efficacy.

LEARNING OBJECTIVES

To raise the awareness of potential drug-nutrient interactions and influence on clinical outcomes. To identify factors that can promote drug-nutrient interactions and contribute to nutrition and/or therapeutic failure. To be aware of different types of drug-nutrient interactions. To understand complex underlying mechanisms responsible for drug-nutrient interactions. To learn basic rules for the administration of medications during tube-feeding.

Identification of the cytochrome P450 enzymes involved in the metabolism of cisapride: in vitro studies of potential co-medication interactions

Cisapride is a prokinetic drug that is widely used to facilitate gastrointestinal tract motility. Structurally, cisapride is a substituted piperidinyl benzamide that interacts with 5-hydroxytryptamine-4 receptors and which is largely without central depressant or antidopaminergic side-effects. The aims of this study were to investigate the metabolism of cisapride in human liver microsomes and to determine which cytochrome P-450 (CYP) isoenzyme(s) are involved in cisapride biotransformation. Additionally, the effects of various drugs on the metabolism of cisapride were investigated. The major in vitro metabolite of cisapride was formed by oxidative N-dealkylation at the piperidine nitrogen, leading to the production of norcisapride. By using competitive inhibition data, correlation studies and heterologous expression systems, it was demonstrated that CYP3A4 was the major CYP involved. CYP2A6 also contributed to the metabolism of cisapride, albeit to a much lesser extent. The mean apparent K(m) against cisapride was 8.6+/-3.5 microM (n = 3). The peak plasma levels of cisapride under normal clinical practice are approximately 0.17 microM; therefore it is unlikely that cisapride would inhibit the metabolism of co-administered drugs. In this in vitro study the inhibitory effects of 44 drugs were tested for any effect on cisapride biotransformation. In conclusion, 34 of the drugs are unlikely to have a clinically relevant interaction; however, the antidepressant nefazodone, the macrolide antibiotic troleandomycin, the HIV-1 protease inhibitors ritonavir and indinavir and the calcium channel blocker mibefradil inhibited the metabolism of cisapride and these interactions are likely to be of clinical relevance. Furthermore, the antimycotics ketoconazole, miconazole, hydroxy-itraconazole, itraconazole and fluconazole, when administered orally or intravenously, would inhibit cisapride metabolism.

Overview of medical therapy for gastroesophageal reflux disease

There appears to be a hierarchy in the efficacy of therapies that are directed against GERD. A summary of this hierarchy, including therapies [table: see text] not approved by the U.S. Food and Drug Administration, is presented in Table 4. The individual practitioner must evaluate the appropriate point at which to place each patient on this hierarchy. Whether it is best to begin with the drug with the highest efficacy and step-down as possible for maintenance, never to step down, or to start with a less efficacious therapy and step up must also be individualized because there are no clear data to support a universal approach to all or even most GERD patients.

Saliva and esophageal protection

There has been much interest in recent years in the potential protective role of saliva in the esophagus. Variables such as salivary volume and neutralizing capacity have been studied both during basal conditions and in response to esophageal acid exposure, in healthy subjects and in patients with esophagitis. In addition to its known neutralizing capacity, saliva also contains growth factors. These polypeptides (of which epidermal growth factor has been studied most) have cytoprotective and healing properties in various segments of the gastrointestinal tract. Therefore, a deficiency in one or more of these growth factors might be a contributing factor in the development of gastroesophageal reflux disease (GERD) or its complication, such as Barrett's metaplasia. However, human studies have produced contradictory results regarding salivary growth factor deficiency in such patients. Current methods of investigation make it difficult to assess the importance of saliva in GERD. This may be due in part to the multifactorial nature of the disease and the difficulty in long-term, selective manipulation of salivary function in humans. Given the present data in the literature, it is therefore unknown if saliva plays an important role in esophageal protection.

Functional gut disorders: from motility to sensitivity disorders. A review of current and investigational drugs for their management

Functional gut disorders include several clinical entities defined on the basis of symptom patterns (e.g., functional dyspepsia, irritable bowel syndrome, functional abdominal pain, functional abdominal bloating), for which there is no established pathophysiological mechanism. Because there is no well-defined pathophysiological target, treatment should be aimed at symptom improvement. Prokinetics and antispasmodics have been widely used in the treatment of functional gut disorders on the assumption that disordered motility is the underlying cause of symptoms, and symptom improvement is indeed achievable with these compounds in some, but not all, patients with features of hypo- or hypermotility, respectively. In the first part of this review, we cover the basic pharmacology and discuss the rationale for the clinical use of prokinetics and antispasmodics. On the other hand, in the past few years, the explosive growth in the research focusing on visceral sensitivity and visceral reflexes has suggested that at least some patients with functional gut disorders have altered visceral perception. Thus, the second part of the review covers these developments and focuses on studies addressing the issue of drugs modulating visceral sensitivity.

Gastroesophageal reflux in children

Gastroesophageal reflux (GER) is a common disorder in infants and children with a high rate of spontaneous resolution. Some children, however, will continue to have problems and progress from functional GER to pathogenic GER. In children with functional GER, diagnostic testing and pharmacologic treatment is unnecessary. In more involved cases, there are a number of tests available that help to quantify and qualify the extent of disease. Treatment begins with conservative measures and progresses to acid neutralization/supression and medications to enhance motility. Should medical management fail to control the consequences of reflux disease, surgical intervention is warranted.

The effect of mosapride, a novel prokinetic, on acid reflux variables in patients with gastro-oesophageal reflux disease

BACKGROUND

Mosapride is a novel prokinetic agent facilitating acetylcholine release from the enteric cholinergic neurones through a selective 5-HT4 receptor agonistic action. It is also active through its main metabolite M1, which is a 5-HT3 antagonist. The importance of motor dysfunction in the pathogenesis of gastro-oesophageal reflux disease (GERD) makes it interesting to examine the effect of mosapride on oesophageal acid exposure.

METHODS

The effect of mosapride on oesophageal 24-h acid reflux variables was studied in 21 patients with GERD symptoms and a pre-entry total acid exposure time (pH < 4) of more than 5%. Ambulatory pH monitoring was performed after treatment with 40 mg mosapride citrate or placebo q.d.s. for 2 days in random order, using a double-blind crossover technique, with a washout period of at least 5 days.

RESULTS

Mosapride was significantly more effective than placebo in decreasing the total number of reflux episodes, the total number of reflux episodes lasting more than 5 min and the total time, as well as the amount of day time, of intra-oesophageal pH below 4. Consequently, mosapride also significantly improved total acid clearance time.

CONCLUSION

Mosapride 40 mg q.d.s. is effective in decreasing acid reflux in the oesophagus in patients with GERD and therefore has the potential to be effective in the treatment of this disease.

Effects of metoclopramide on gastrointestinal myoelectric activity in rats

AIM: To investigate the effects of metoclopramide (MCP) action on myoelectric activity in the antrum and small intestine.

METHODS: Ten healthy male Wistar rats, weighing 250-350 g, were anesthetized with ketamine hydrochloride (100 mg/kg, intramuscularly). Four pairs of bipolar stainless steel electrodes 3 mm apart were implanted on the serosal surface of the antrum at one, 10 and 20 cm distal to the pylorus. Five to ten days following the operation, the gastrointestinal myoelectric activity of fasted rats after intramuscular injection of 2.5, six and 12 mg/kg MCP was recorded using a 8-channel EEG machine, and these values were quantitatively compared with the myoelectric activity after saline injection.

RESULTS: In fasted rats, 2.5 mg/kg MCP increased the amplitude of spike activity (402.0 ± 138.4 μV, vs 345 ± 163.4 μV, P < 0.05) and the percentage of the slow wave-containing spike bursts (60.4% ± 22.0% vs 47.4% ± 22.5%, P < 0.01) of small intestine (1 cm distal to the pylorus), but did not affect the myoelectric activity of the antrum. Six and 12 mg/kg MCP increased the amplitude of both the slow wave (332.8 ± 200.1 μV vs 191.2 ± 143.9 μV, P < 0.01; 330.0 ± 197.1 μV vs 191.2 ± 143.9 μV, P < 0.05) and the spike activity of the antrum (180.5 ± 69.7 μV vs 121.8 ± 63.3 μV, P < 0.05; 174.5 ± 71.7 μV vs 123.8 ± 63.3 μV, P < 0.05), while in small intestine (1 cm distal to the pylorus) only the amplitude of spike activity (407.3 ± 179.0 μV vs 345.0 ± 163.4 μV, P < 0.05; 456.0 ± 145.4 μV vs 345.0 ± 163.4 μV, P < 0.05) and the percentage of the slow wave containing spike bursts (61.7% ± 26.5% vs 47.4% ± 22.5%, P < 0.01; 59.1% ± 17.3% vs 47.4% ± 22.5%, P < 0.01) was increased and the latent period significantly prolonged (2.5 ± 0.35 min vs 0.77 ± 0.18 min, P < 0.01).

CONCLUSION: Different mechanisms may be involved in enhancing the myoelectric activity of the antrum and small intestine following MCP administration.

Medical Therapy of GERD: current state of the art

A proton pump inhibitor is the most cost-effective choice for severe disease and, in low doses, for moderate disease. Patients with mild disease and infrequent relapses can be managed with a H2-receptor antagonist, an antacid, or cisapride.

The diagnosis and management of gastroesophageal reflux disease

GERD is a common clinical problem. Generally, its clinical presentation and management are straightforward. Greater awareness of the numerous extraesophageal manifestations of the disease aids patients and physicians in appropriate recognition and treatment. Medical therapy is effective in the majority of cases but often requires long-term medication for acceptable symptom control. A small, but significant proportion of patients presents with or develops complications of GERD, most importantly Barrett's esophagus. Although the logistics of long-term surveillance of persons with Barrett's esophagus is unclear, the association of this metaplastic change with esophageal adenocarcinoma underscores the importance of regular follow-up.

Pharmacological management of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) ranges from episodic symptomatic reflux without oesophagitis to severe oesophageal mucosal damage, such as Barrett's metaplasia or peptic stricture. The multifactorial pathogenesis of GORD prevents medical cure of the disease. GORD is a chronic disease with a high tendency to relapse, requiring a long term treatment strategy in practically all patients. Complete healing of all mucosal lesions is not necessarily the aim of treatment in all patients. In milder forms of reflux disease, symptom relief is the most important goal. Many patients with mild GORD do well on symptomatic self-care with antacids and/or alginate. In addition, lifestyle changes should be advised to all patients: these improve symptoms and enhance the efficacy of therapy. In the acute treatment of GORD the prokinetic drug cisapride has been shown to be effective in relieving symptoms and healing grade I to II oesophagitis. Cisapride decreases symptomatic and endoscopic relapse in patients with mild GORD. Histamine H2-receptor antagonists are effective in relieving reflux symptoms in about 50% of patients, but with regard to healing, H2-antagonists appear to be mainly effective in grades I and II and not in higher grades of oesophagitis. Maintenance treatment with H2-antagonists is mainly symptomatically effective in patients with mild GORD. Proton pump inhibitors (PPIs) provide significantly higher healing rates of reflux oesophagitis than H2-antagonists, even in the more severe cases of oesophagitis and Barrett's ulcers. PPIs are also effective in patients with oesophagitis refractory to treatment with H2-antagonists. PPIs have become the drugs of first choice in healing of all patients with more severe forms of reflux oesophagitis, and increasingly also for patients with milder forms of oesophagitis, certainly those who fail to respond to other drugs. In maintenance treatment of GORD, PPIs are the most effective drugs, offering the possibility of keeping nearly all patients in remission with adjusted doses. Current patient data of up to 5 years indicate the safety of this strategy for this period, but the exact consequences of strong acid inhibition over a longer period still have to be clarified. At present, all but a few patients with GORD can be managed adequately by medical therapy.

Nutrition of critically ill people

There has been an increasing awareness over the past few years of malnourishment in hospital patients (Horwood 1990, Wallace 1993). Critically ill patients are a particularly vulnerable group as their physical problems can mean depleted energy reserves and an increase in energy consumption. The aim here is to consider ways in which malnutrition can be avoided in critically ill people. Different methods to provide patients with adequate nutrition, and the associated complications, are also discussed. To give critically ill patients the best possible chance of survival, intensive care staff need to be aware of recent developments in clinical nutrition. A multidisciplinary approach to nutrition is essential to achieve the best possible outcome for patients in intensive care units (ICUs).

Gastrointestinal motility disorders in scleroderma

After the skin, the gastrointestinal tract is the second most common target of systemic sclerosis. The major clinical manifestations include gastroesophageal reflux, small bowel bacterial overgrowth, malnutrition, and intestinal pseudoobstruction. Treatment is symptomatic and supportive. Gastroesophageal reflux can usually be adequately managed with prokinetic drugs, omeprazole, and judicious use of antireflux surgery. If Barrett's esophagus is present, periodic endoscopic monitoring for development of dysplastic changes or adenocarcinoma is indicated. Bacterial overgrowth usually responds to rotating antibiotics and prokinetic drugs. Malnutrition and intestinal pseudoobstruction remain the major problems and often home total parenteral nutrition is required. Intestinal pseudoobstruction occurs in two phases: an early, neuropathic phase may respond to prokinetic drugs (metoclopramide, cisapride, octreotide, and erythromycin) and dietary modification (low-residue diets, vitamin supplementation). In the late myopathic phase, therapy is usually ineffective. Treatment consists of nutritional support. Careful manometric and radiographic localization of affected segments of stomach and small and large intestines may allow judicious surgical resection or venting procedures to reduce symptoms in this unfortunate group of patients.

The importance of 5-hydroxytryptamine receptors in the gut

Most of the 5-hydroxytryptamine (5-HT) present in the adult human body is located in the gastrointestinal tract. The vast majority is contained in enteroendocrine cells, the rest exists mainly in myenteric interneurons separated from the mucosa by an intraenteric barrier. Physiological studies suggest that 5-HT plays a vital role in mediating both sensory and reflex responses to gastrointestinal stimuli and, thus, this transmitter is closely implicated in gut reactions. This review outlines some of the evidence for different 5-HT receptors, summarizes the role of 5-HT in mediating gut sensitivity and motor activity, secretion and more complex activities, such as emesis and diarrhoea and identifies the clinical role of drugs acting on 5-HT receptors in the treatment of emesis, diarrhoea, the control of abdominal pain and discomfort and the rectification of gastrointestinal motility.

Review article: drug therapy for reflux oesophagitis

Gastro-oesophageal reflux disease is a common disorder and symptoms can be mild to severe. Management of the disease should be individualized. Life-style changes are important for all patients. Drug therapy is often necessary but only very few patients with severe disease need surgical treatment. The purpose of this article is to focus on drug therapy and to review the clinical trials of all the drugs used for gastro-oesophageal reflux disease. Thereafter, judged solely on the data derived from these trials, a practical approach to the management of gastro-oesophageal reflux disease is suggested.