Baclofen and gastroesophageal reflux disease: seeing the forest through the trees

Regurgitation, eructation, and supragastric belch: retrograde esophageal motility, disorders, and treatment

PURPOSE OF REVIEW

This review describes pathologic conditions of retrograde flow into the esophagus along with recent therapeutic advances and treatment options.

RECENT FINDINGS

The esophagus facilitates anterograde and retrograde movement of contents, the latter of which is mediated by transient lower esophageal sphincter relaxations (TLESRs). Gastroesophageal reflux disease (GERD) often includes esophageal-specific symptoms such as heartburn or regurgitation. Volume regurgitation responds less frequently to acid suppression with proton pump inhibitors (PPIs) than heartburn, given its relationship with incompetence of the esophagogastric junction (EGJ) and increased frequency of TLESRs. Therefore, although the refluxate pH can be altered with PPIs, the frequency of reflux episodes is generally not reduced and surgical and endoscopic treatments may be favored. Other instances of abnormal retrograde esophageal flow respond better to medical therapy, or lifestyle interventions. Compared to gastric belching because of increased stomach distension, supragastric belching is caused by intake of air from pharynx into the esophagus followed by rapid expulsion of air. These conditions can be distinguished on esophageal tests such as high-resolution manometry and are likely to respond to behavioral modifications.

SUMMARY

Retrograde flow into the esophagus can be a normal occurrence, but diagnostic testing to distinguish causes can guide appropriate intervention.

Baclofen as a therapeutic option for gastroesophageal reflux disease: A systematic review of clinical trials

Background

The main components of gastroesophageal reflux disease (GERD) management include a combination of medications and lifestyle modifications; Nevertheless, based on the severity of symptoms and their response to medications, other treatments could be considered. Baclofen has been demonstrated in studies to relieve GERD symptoms. The current study aimed to precisely address the effects of baclofen on the treatment of GERD and its characteristics.

Methods

A systematic search was carried out in Pubmed/Medline, Cochrane CENTRAL, Scopus, Google Scholar, Web of Science, and clinicaltrials.gov up to December 10, 2021. The search terms included baclofen, GABA agonists, GERD, and reflux.

Results

We selected 26 papers that matched the inclusion criteria after examining 727 records. Studies were classified into four categories based on the study population and reported outcomes: (1) adults, (2) children, (3) patients with gastroesophageal reflux-induced chronic cough, (4) hiatal hernia patients. The results revealed that baclofen can significantly improve reflux symptoms and pH-monitoring and manometry findings to different degrees in all four mentioned categories; although its effect on pH-monitoring parameters seems less significant than the other parameters. Mild neurological and mental status deterioration were the most reported side effects. However, side effects occurred in a portion of less than 5% of short-term users and nearly 20% of long-term users.

Conclusion

In PPI-resistant patients, a trial of adding baclofen to the PPI may be helpful. Baclofen therapies may be more beneficial for symptomatic GERD patients who also report concurrent conditions including alcohol use disorder, non-acid reflux, or obesity.

Systematic review registration

https://clinicaltrials.gov/.

Behavioral therapy is superior to follow-up without intervention in patients with supragastric belching-A randomized study

BACKGROUND

Behavioral therapy (BT) has been proven effective in the treatment of supragastric belching (SGB) in open studies. The aim was to compare BT to follow-up without intervention in patients with SGB in a randomized study.

METHODS

Forty-two patients were randomized to receive 5 sessions of BT, comprising diaphragmatic breathing exercises, or to follow-up without intervention. Patients were evaluated at 6 months, at which point the control group was also offered BT and evaluated after another 6 months. The frequency and intensity of belching and mental well-being were evaluated with a visual analog scale (VAS). Depression, anxiety, and health-related quality of life (HRQoL) were evaluated with four questionnaires: BDI, BAI, 15D, and RAND-36.

KEY RESULTS

The frequency and intensity of SGB were significantly lower in the therapy group (n = 19) than in the control group (n = 18) at the 6-month control (p < 0.001). When all patients (n = 36) were evaluated 6 months after BT, in addition to relief in the frequency and intensity of belching (p < 0.001), mental well-being had also improved (p < 0.05). Of all 36 patients, 27(75%) responded to BT. Depression scores were lower after therapy (p < 0.05). Only minor changes occurred in anxiety and HRQoL.

CONCLUSIONS AND INFERENCES

Behavioral therapy is superior to follow-up without intervention in patients with SGB in reducing belching and depression; it also improves mental well-being but has only a modest effect on anxiety and HRQoL.

Arecae pericarpium extract induces porcine lower-esophageal-sphincter contraction via muscarinic receptors

Background

Gastroesophageal reflux disease (GERD) is associated with lower esophageal sphincter (LES) incompetence. In some patients, GERD is refractory to acid reduction therapy which is the main treatment for GERD. So far, medications that can increase LES tone are few. Arecae pericarpium (A. pericarpium) is a medication in Traditional Chinese Medicine known to promote intestinal motility.

Methods

We investigated the effect of A. pericarpium extracts on porcine LES motility. In addition, we used tetrodotoxin (TTX) and atropine to study the underlying mechanism of A. pericarpium extracts-induced contractions of LES.

Results

The results of this study showed that A. pericarpium extracts and their main active ingredient, arecoline, can induce the contractions of porcine LES sling and clasp muscles in a dose-response manner. TTX did not have an inhibitory effect on the contractions induced by A. pericarpium extracts and arecoline in LES. However, atropine significantly inhibited A. pericarpium extracts- and arecoline-induced contractions of LES.

Conclusion

A. pericarpium extracts can induce the contractions of porcine LES in a dose dependent manner, possibly through muscarinic receptors, and hence, may be worth developing as an alternative therapy for GERD.

The Medical Management of Gastroesophageal Reflux Disease: A Narrative Review

OBJECTIVE

The medical management of gastroesophageal reflux disease (GERD) continues to evolve. Our aim was to systematically assess the literature to provide an updated review of the evidence on lifestyle modifications and pharmacological therapy for the management of GERD.

BACKGROUND

The cornerstones of GERD medical management consist of lifestyle modifications and pharmacologic agents. Most recently, evidence has emerged linking anti-reflux pharmacologic therapy to adverse events, such as kidney injury, metabolic bone disease, myocardial infarction, and even dementia, among others.

METHODS

A systematic search of the databases of PubMed/MEDLINE, Embase, and Cochrane Library was performed for articles on the medical management of GERD between inception and March 1, 2021.

CONCLUSION

Although pharmacological therapy has been associated with potential adverse events, further research is needed to determine if this association exists. For this reason, lifestyle modifications should be considered first-line, while pharmacologic therapy can be considered in patients in whom lifestyle modifications have proven to be ineffective in controlling their symptoms or cannot institute them. Naturally, extra-esophageal causes for GERD-like symptoms must be considered on suspected high-risk patients and excluded before considering treatment for GERD.

Baclofen therapeutics, toxicity, and withdrawal: A narrative review

Baclofen is an effective therapeutic for the treatment of spasticity related to multiple sclerosis, spinal cord injuries, and other spinal cord pathologies. It has been increasingly used off-label for the management of several disorders, including musculoskeletal pain, gastroesophageal reflux disease, and alcohol use disorder. Baclofen therapy is associated with potential complications, including life-threatening toxicity and withdrawal syndrome. These disorders require prompt recognition and a high index of suspicion. While these complications can develop following administration of either oral or intrathecal baclofen, the risk is greater with the intrathecal route. The management of baclofen toxicity is largely supportive while baclofen withdrawal syndrome is most effectively treated with re-initiation or supplementation of baclofen dosing. Administration of other pharmacologic adjuncts may be required to effectively treat associated withdrawal symptoms. This narrative review provides an overview of the historical and emerging uses of baclofen, offers practical dosing recommendations for both oral and intrathecal routes of administration, and reviews the diagnosis and management of both baclofen toxicity and withdrawal.

GABAB Receptor Chemistry and Pharmacology: Agonists, Antagonists, and Allosteric Modulators

The GABA_B receptors are metabotropic G protein-coupled receptors (GPCRs) that mediate the actions of the primary inhibitory neurotransmitter, γ-aminobutyric acid (GABA). In the CNS, GABA plays an important role in behavior, learning and memory, cognition, and stress. GABA is also located throughout the gastrointestinal (GI) tract and is involved in the autonomic control of the intestine and esophageal reflex. Consequently, dysregulated GABA_B receptor signaling is associated with neurological, mental health, and gastrointestinal disorders; hence, these receptors have been identified as key therapeutic targets and are the focus of multiple drug discovery efforts for indications such as muscle spasticity disorders, schizophrenia, pain, addiction, and gastroesophageal reflex disease (GERD). Numerous agonists, antagonists, and allosteric modulators of the GABA_B receptor have been described; however, Lioresal^® (Baclofen; β-(4-chlorophenyl)-γ-aminobutyric acid) is the only FDA-approved drug that selectively targets GABA_B receptors in clinical use; undesirable side effects, such as sedation, muscle weakness, fatigue, cognitive deficits, seizures, tolerance and potential for abuse, limit their therapeutic use. Here, we review GABA_B receptor chemistry and pharmacology, presenting orthosteric agonists, antagonists, and positive and negative allosteric modulators, and highlight the therapeutic potential of targeting GABA_B receptor modulation for the treatment of various CNS and peripheral disorders.

Efficacy and Safety of Esomeprazole for the Treatment of Reflux Symptoms in Patients with Gastroesophageal Reflux Disease: A Systematic Review and Meta-Analysis

Background:

We investigated the efficacy of esomeprazole for the treatment of gastroesophageal reflux disease (GERD) in a meta-analysis of clinical trials results.

Methods:

Medline, Embase, PubMed and Web of Science databases were systematically searched for suitable studies, and double-blind, randomized controlled trials (RCTs) were involved. A meta-analysis of RCTs was performed to analyze the efficacy of esomeprazole on clinical outcomes that associated with the severity of GERD.

Results:

A total of 8 clinical trials were selected in our meta-analysis (N=4495, patients with GERD). Esomeprazole treatment yielded a significant improvement in clinical signs and symptoms of GERD compared to placebo group. Funnel plot and Egger test showed there was no significant bias in the publication. Cochrane collaboration tool and Jadad scale were used to indicate that all 8 RCTs were of high quality. The results of Galbraith radial plot showed that no study was the major source of heterogeneity. Esomeprazole treatment significantly decreased the relapse rates more than that of placebo group (RR = 0.729; 95% CI: 0.670 to 0.794; P<0.001). It seems to be lower rates of heartburn (RR = 0.747; 95%CI: 0.665–0.839; P <0.001) and epigastric pain (RR = 0.795; 95%CI: 0.679–0.932; P =0.005) in esomeprazole-treated group compared with the placebo group. Moreover, serious adverse events was less likely to happen after esomeprazole therapy (RR = 1.406, 95% CI: 1.030–1.918; P =0.032).

Conclusion:

Compared with the control group, esomeprazole is a promising therapeutic agent that improves the management of patients with GERD.

Rethinking gastroesophageal reflux disorder

Gastroesophageal reflux disease (GERD) is a common clinical condition for which our understanding has evolved over the past decades. It is now considered a cluster of phenotypes with numerous anatomical and physiological abnormalities contributing to its pathophysiology. As such, it is important to first understand the underlying mechanism of the disease process for each patient before embarking on therapeutic interventions. The aim of our paper is to highlight the mechanisms contributing to GERD and review investigations and interpretation of these results. Finally, the paper reviews the available treatment modalities for this condition, ranging from medical intervention, endoscopic options through to surgery and its various techniques.

Non-acid Reflux: When It Matters and Approach to Management

PURPOSE OF REVIEW

This narrative review focuses on the presentation, contributing factors, diagnosis, and treatment of non-acid reflux. We also propose algorithms for diagnosis and treatment.

RECENT FINDINGS

There is a paucity of recent data regarding non-acid reflux. The recent Porto and Lyon consensus statements do not fully address non-acid reflux or give guidance on classification. However, recent developments in the lung transplantation field, as well as older data in the general population, argue for the importance of non-acid reflux. Extrapolating from the Porto and Lyon consensus, we generally classify pathologic non-acid reflux as impedance events > 80, acid exposure time < 4%, and positive symptom correlation on a standard 24-h pH/impedance test. Other groups not meeting this criteria also deserve consideration depending on the clinical situation. Potential treatments include lifestyle modification, increased acid suppression, alginates, treatment of esophageal hypersensitivity, baclofen, buspirone, prokinetics, and anti-reflux surgery in highly selected individuals. More research is needed to clarify appropriate classification, with subsequent focus on targeted treatments.

New Developments in the Diagnosis and Management of Gastroesophageal Reflux

PURPOSE OF REVIEW

To examine recent key developments in the pathophysiology, diagnosis, and treatment of gastroesophageal reflux disease (GERD).

RECENT FINDINGS

Newer research has suggested cytokine-mediated inflammation may play a role in the physiology of GERD, implying that the underlying mechanism may not be entirely related to chemical damage due to acid. Aided by novel technologies, diagnostic testing is also moving toward elucidating individual mechanisms and better defining specific GERD phenotypes with the goal of providing directed therapy. This is especially important in current times given the increase in coverage of adverse events reportedly linked to long-term proton pump inhibitor use.

SUMMARY

As patients are looking for potential alternatives, we highlight the key recent updates in pathophysiology and understanding of GERD and current medical and endoscopic/surgical options and explore the exciting treatments in the pipeline.