Gastroesophageal reflux disease and baclofen: is there a light at the end of the tunnel?

Efficacy of Baclofen as Add-on Therapy for Refractory Gastroesophageal Reflux Disease: A Meta-analysis

OBJECTIVES

As a GABAB receptor agonist, baclofen has demonstrated efficacy in alleviating symptoms of refractory gastroesophageal reflux disease (r-GERD). This meta-analysis aims to evaluate the safety and effectiveness of baclofen as an add-on therapy for this condition.

METHOD

We conducted a comprehensive search of the PubMed, Embase, and Web of Science databases for studies published up until October 2023. Subsequently, we performed a meta-analysis encompassing all eligible trials.

RESULTS

From 719 records, 10 studies were included, most of these studies were moderate risk. The findings demonstrated that the addition of baclofen as a supplementary treatment effectively improves symptoms (GERD Q score) in r-GERD (standardized mean difference=-0.78, 95% CI: -1.06 to -0.51, I2=0%). The addition of this treatment also resulted in a decrease in the frequency of nonacidic reflux episodes (standardized mean difference=-0.93, 95% CI: -1.49 to -0.37, I2=63%) and an improvement in DeMeester scores (standardized mean difference=-0.82, 95% CI: -1.61 to -0.04, I2=81%) among patients with r-GERD when compared with the use of proton pump inhibitor (PPI) drugs alone. However, no significant disparity was observed in terms of reducing acid reflux episodes (standardized mean difference=-0.12, 95% CI: -0.49 to 0.19, I2=0%) and proximal reflux (standardized mean difference=-0.47, 95% CI: -1.08 to 0.14, I2=60%).

CONCLUSION

Baclofen as an add-on treatment can effectively improve the symptoms of patients with r-GERD and reduce the incidence of nonacidic reflux and improve DeMeester score. However, long-term use of baclofen leads to an increased incidence of side effects and is not effective in reducing the occurrence of acid reflux.

How safe are heartburn medications and who should use them?

INTRODUCTION

Heartburn is a frequent symptom occurring in daily clinical practice and is mainly associated with gastroesophageal reflux disease (GERD). However, it can be stimulated by various factors and diseases other than GERD can present with heartburn. Therefore, physicians must be very careful in distinguishing GERD from non-GERD conditions in their patients, particularly when heartburn is refractory to anti-reflux medications.

AREAS COVERED

The aim of this narrative review was to analyze the medical literature regarding the prevalence of heartburn and the various clinical disorders which can be present with this symptom. The type of medications usually adopted for treating heartburn and their grade of safety have been reviewed using an extensive computerized (Medline/PubMed) search with particular focus on the last 20 years.

EXPERT OPINION

Many drugs can be used for relieving heartburn in patients with GERD, although PPIs are the pharmacological agents with the greatest efficacy. However, it must be highlighted that many non-GERD conditions may present clinically with this symptom whose intensity does not differ between GERD and functional esophageal disorders, which represent about 50% of all patients with suspected GERD. It is very important to identify these functional conditions because their treatment differs completely from that of GERD.

Clinical trial: a controlled trial of baclofen add-on therapy in PPI-refractory gastro-oesophageal reflux symptoms

BACKGROUND

Proton pump inhibitors (PPI) have no effect on non-acid reflux events which can continue to provoke gastro-oesophageal reflux disease (GERD) symptoms. Baclofen, a γ-aminobutyric acid agonist, can decrease non-acid reflux but its symptomatic benefit in refractory GERD symptoms is understudied.

AIMS

To assess the efficacy of baclofen 10 mg t.i.d. vs placebo as add-on therapy in PPI-refractory GERD symptoms, in a randomised, double-blind, placebo-controlled study.

METHODS

Patients with persisting typical GERD symptoms on b.i.d. PPI therapy were randomised to 4 weeks of baclofen 10 mg or placebo t.i.d. Before and after treatment, patients underwent 24 h impedance-pH monitoring on-PPI. Throughout the study, patients filled out ReQuest diaries. Data were analysed using mixed models.

RESULTS

About 60 patients were included (age 47.5 years [range 19-73], 41f/19 m), 31 patients were randomised to baclofen. One patient withdrew consent and five in the baclofen group stopped treatment due to side effects. There was a trend towards a better response for general wellbeing in the baclofen-treated group compared to placebo (p = 0.06). When subdividing patients according to symptom association probability (SAP), only the SAP+ (n = 25) group improved significantly with baclofen (p_corr  = 0.02), and worsened with placebo (p_corr  = 0.008). The total number of reflux events decreased over time (p = 0.01), mainly due to the baclofen condition (p_corr  = 0.1). The number of reflux events with a high proximal extent dropped significantly after baclofen (p_corr  = 0.009), but not placebo.

CONCLUSION

Baclofen decreases several reflux parameters in PPI refractory GERD symptoms, but pH-impedance monitoring is necessary before treatment as only SAP+ patients experience clinical benefit after 4 weeks.

Pharmacological Management of Gastro-Esophageal Reflux Disease: An Update of the State-of-the-Art

Gastro-esophageal reflux disease (GERD) is a highly prevalent, chronic disorder, whose knowledge remains limited and the management of these patients changes continuously. This review provides a summary of the most recent advancements in the pathogenesis of this disease and the new drugs introduced into the market to overcome some of the unmet needs of traditional therapies. Nowadays, the most fruitful diagnostic examinations are 24-hour impedance-pH monitoring, which allows us to separate true NERD from esophageal functional disorders and high-resolution manometry, which helps to exclude the existence of motility disorders sharing the same symptoms of GERD. Proton pump inhibitors (PPIs) remain the first-choice therapy in the treatment of GERD, but a consistent proportion of these patients continue to experience symptoms despite their intake. These cases pertain mainly to the subpopulation with non-erosive reflux disease (NERD) and represent very challenging clinical situations, because it is mandatory to understand the reasons for PPI failure. The management of these difficult patients requires necessarily to test them and avoid the use of empiric treatments that are often unsuccessful, costly and potentially dangerous. Recently, several new drugs have been used to increase the defensive properties of this mucosa with promising results in randomized clinical trials.

A review of pharmacotherapy for treating gastroesophageal reflux disease (GERD)

INTRODUCTION

Medical therapy of gastroesophageal reflux disease (GERD) is based on the use of proton pump inhibitors (PPIs) as first choice treatment. Despite their effectiveness, about 20-30% of patients report an inadequate response and alternative drugs are required. Areas covered: This review provides an overview of current pharmacotherapy for treating GERD by showing the results of PPIs, reflux inhibitors, antidepressants and mucosa protective medications. Expert opinion: Medical therapy of GERD does not definitely cure the disease, because even PPIs are not able to change the key factors responsible for it. However, they remain the mainstay of medical treatment, allowing us to alleviate symptoms, heal esophagitis and prevent complications in the majority of cases. Nevertheless, many patients do not respond, because acid does not play any pathogenetic role. Prokinetics and reflux inhibitors have the potential to control motor abnormalities, but the results of clinical trials are inconsistent. Antidepressant drugs are effective in specific subgroups of NERD patients with visceral hypersensitivity, but larger, controlled clinical studies are necessary. Protective drugs or medical devices have been recently adopted to reinforce mucosal resistance and preliminary trials have confirmed their efficacy either combined with or as add-on medication to PPIs in refractory patients.

The gastric accommodation response to meal intake determines the occurrence of transient lower esophageal sphincter relaxations and reflux events in patients with gastro-esophageal reflux disease

BACKGROUND

Gastro-esophageal reflux (GER), the retrograde flow of gastric contents into the esophagus is a physiologic phenomenon, which can evoke symptoms and/or lesions in the esophagus (=gastro-esophageal reflux disease or GERD). Proton pump inhibitors (PPIs) reduce gastric acidity; however, as they are unable to control transient lower esophageal sphincter relaxations (TLESRs), the main mechanism for reflux in GERD, they do not abolish reflux. TLESRs occur predominantly in the postprandial period, and they are believed to be triggered by gastric distention. Gastric accommodation (GA) is the physiologic response to gastric distention and serves to prevent a rise in gastric wall tension during food intake. We aimed to study the relationship between GA and TLESRs, as they both are triggered by gastric distention.

METHODS

We studied 12 GERD patients (average age 37 years [range 18-62], 7m/5f) and nine healthy volunteers (average age 27 years [range 22-36], 2m/7f) using high resolution manometry-impedance measurement before and after a mixed meal challenge. We determined the number of TLESRs (with or without reflux) and measured pre- and postprandial IGP. The change in IGP between the pre- and postprandial period (ΔIGP) is used as surrogate for GA. We also measured LES pressure before and after the meal and calculated the change (ΔLESp).

KEY RESULTS

There were no statistical differences between pre- and postprandial IGP in GERD and healthy volunteers and similarly, there was no significant difference between pre- and postprandial LES pressures in GERD patients and healthy volunteers. The number of TLESRs (with or without reflux) was similar in GERD and healthy volunteers. More importantly, we did observe a negative correlation between ΔIGP and the number of TLESRs, irrespective of whether they were associated with reflux or not, in the GERD patients (without reflux r = -0.67, p = 0.017; with reflux r = -0.81, p = 0.0014). The same observations were found in healthy volunteers, where ΔIGP and the number of TLESRs are significantly inversely correlated (without reflux r = -0.87, p = 0.0045; with reflux r = -0.75, p = 0.021). We could not establish a correlation between ΔLESp and the number of TLESRs, neither in GERD patients nor in healthy volunteers.

CONCLUSIONS & INFERENCES

This is the first study showing a clear negative correlation between ΔIGP and the number of TLESRs, irrespective of whether they were associated with reflux or not, both in GERD patients and in healthy subjects. These results suggest that TLESRs and GA are closely linked, probably through activation of mechanoreceptors involved in triggering of TLESRs.

Evaluation of Esophageal Motor Function With High-resolution Manometry

For several decades esophageal manometry has been the test of choice to evaluate disorders of esophageal motor function. The recent introduction of high-resolution manometry for the study of esophageal motor function simplified performance of esophageal manometry, and revealed previously unidentified patterns of normal and abnormal esophageal motor function. Presentation of pressure data as color contour plots or esophageal pressure topography led to the development of new tools for analyzing and classifying esophageal motor patterns. The current standard and still developing approach to do this is the Chicago classification. While this methodical approach is improving our diagnosis of esophageal motor disorders, it currently does not address all motor abnormalities. We will explore the Chicago classification and disorders that it does not address.

Nocturnal weakly acidic reflux promotes aspiration of bile acids in lung transplant recipients

BACKGROUND

Gastroesophageal reflux (GER) and aspiration of bile acids have been implicated as non-alloimmune risk factors for the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation. The aim of our study was to investigate the association between GER and gastric aspiration of bile acids and to establish which reflux characteristics may promote aspiration of bile acids into the lungs and may feature as a potential diagnostic tool in identifying lung transplantation (LTx) patients at risk for aspiration.

METHODS

Twenty-four stable LTx recipients were studied 1 year after transplantation. All patients underwent 24-hour ambulatory impedance-pH recording for the detection of acid (pH <4) and weakly acidic (pH 4 to 7) reflux. On the same day, bronchoalveolar lavage fluid (BALF) was collected and then analyzed for the presence of bile acids (Bioquant enzymatic assay).

RESULTS

Increased GER was detected in 13 patients, of whom 9 had increased acid reflux and 4 had exclusively increased weakly acidic reflux. Sixteen patients had detectable bile acids in the BALF (0.6 [0.4 to 1.5] micromol/liter). The 24-hour esophageal volume exposure was significantly increased in patients with bile acids compared to patients without bile acids in the BALF. Acid exposure and the number of reflux events (total, acid and weakly acidic) were unrelated to the presence of bile acids in the BALF. However, both nocturnal volume exposure and the number of nocturnal weakly acidic reflux events were significantly higher in patients with bile acids in the BALF.

CONCLUSIONS

Weakly acidic reflux events, especially during the night, are associated with the aspiration of bile acids in LTx recipients and may therefore feature as a potential risk factor for the development of BOS.

Is the GABA B heterodimer a good drug target?

GABA(B) receptors are a member of the G protein-coupled family of receptors which are generally considered to be excellent drug targets. Cloning of the GABA(B) receptor demonstrated that, unlike other G protein-coupled receptors, it is an obligate heterodimer. Drugs acting at GABA(B) receptors have the potential to treat a wide variety of diseases. Activation of the receptors may have utility in the treatment of pain, drug-dependence, and anxiety, whereas blockade of receptors may have benefit in cognitive disorders and depression. To date, development of drugs has been hampered by the lack of receptor subtypes and the inability to separate therapeutic benefit from side effects such as sedation. Recently, novel compounds that act via an allosteric mechanism have been identified and are providing hope that future drugs may be developed that target this receptor.

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.

Bronchial aspiration in patients after weight loss due to gastric banding

Laparoscopic gastric banding is a surgical treatment of morbid obesity. There are no specific recommendations concerning anesthesia induction in patients having gastric banding. After recent experience of two bronchial aspirations during anesthetic induction in patients with gastric banding, we concluded that esophago-gastric peristalsis in these patients is altered. Such patients should consume only liquid meals the day before the operation, and we propose a rapid-sequence induction as the anesthetic technique. In patients with an expected difficult airway, an awake intubation may be considered.

Sleeve sensor versus high-resolution manometry for the detection of transient lower esophageal sphincter relaxations

Transient lower esophageal sphincter relaxations (TLESRs) are the most important mechanism by which gastroesophageal reflux occurs, and sleeve sensor manometry is the gold standard for detection of TLESRs. The aim of this study was to evaluate manometry with closely spaced sideholes (high-resolution manometry) for the detection of TLESRs as an alternative. In 12 patients with gastroesophageal reflux disease, a 90-min postprandial manometry was performed by using a catheter incorporating both a sleeve sensor and closely spaced sideholes in the esophagogastric junction. TLESRs recorded with both techniques were scored. Reflux during TLESRs was detected by using manometry (common cavity), intraluminal impedance, and pH monitoring. A total of 145 TLESRs were detected by using both techniques, 117 with high-resolution manometry and 108 with sleeve sensor manometry [not significant (NS)]. Manometric signs of reflux during TLESRs detected with high-resolution and sleeve sensor manometry were found in 62.4 and 56.5%, NS, respectively, versus 38.5 and 35.2%, NS on pH-metry and 70.1 and 60.2%, NS on impedance monitoring. TLESRs recognized only with high-resolution manometry were more often accompanied by reflux, as detected with manometry (59.5%) and impedance monitoring (67.6%), than TLESRs recognized only with sleeve sensor manometry (32.1 and 28.6%). High-resolution manometry is at least as accurate as sleeve sensor manometry for the detection of TLESRs.