Codeine induces increased resistance at the esophagogastric junction but has no effect on motility and bolus flow in the pharynx and upper esophageal sphincter in healthy volunteers: A randomized, double-blind, placebo-controlled, cross-over trial

Effects of Codeine on Esophageal Peristalsis in Patients With Ineffective Esophageal Motility: Studies Using High-resolution Manometry

Background/Aims

This study aims to evaluate the effects of acute codeine administration on primary and secondary esophageal peristalsis in patients with ineffective esophageal motility (IEM).

Methods

Eighteen IEM patients (8 women; mean age 37.8 years, range 23-64 years) were enrolled in the study. The patients underwent high-resolution manometry exams, consisting of 10 single wet swallows, multiple rapid swallows, and ten 20 mL rapid air injections to trigger secondary peristalsis. All participants completed 2 separate sessions, including acute administration of codeine (60 mg) and placebo, in a randomized order.

Results

Codeine significantly increased the distal contractile integral (566 ± 81 mmHg∙s∙cm vs 247 ± 36 mmHg∙s∙cm, P = 0.001) and shortened distal latency (5.7 ± 0.2 seconds vs 6.5 ± 0.1 seconds, P < 0.001) for primary peristalsis compared with these parameters after placebo treatment. The mean total break length decreased significantly after codeine treatment compared with the length after placebo (P = 0.003). Codeine significantly increased esophagogastric junction-contractile integral (P = 0.028) but did not change the 4-second integrated relaxation pressure (P = 0.794). Codeine significantly decreased the frequency of weak (P = 0.039) and failed contractions (P = 0.009), resulting in increased frequency of normal primary peristalsis (P < 0.136). No significant differences in the ratio of impaired multiple rapid swallows inhibition and parameters of secondary peristalsis were detected.

Conclusions

In IEM patients, acute administration of codeine increases contraction vigor and reduces distal latency of primary esophageal peristalsis, but has no effect on secondary peristalsis. Future studies are required to further elucidate clinical relevance of these findings, especially in the setting of gastroesophageal reflux disease with IEM.

Systematic Review With Meta-Analysis: Chronic Opioid Use Is Associated With Esophageal Dysmotility in Symptomatic Patients

INTRODUCTION

We aimed to conduct a systematic review and meta-analysis to assess the impact of chronic opioid exposure on esophageal motility in patients undergoing manometric evaluation.

METHODS

Multiple databases were searched through October 2022 for original studies comparing the manometric results of patients who have used chronic opioids (for >90 days) with those who do not. The primary outcomes were esophageal dysmotility disorders. Three high-resolution manometry parameters were conducted as secondary outcomes. A random-effects model was applied to calculate the odds ratio (OR) and means difference (MD) along with a 95% confidence interval (CI).

RESULTS

Nine studies were included in this meta-analysis. Opioid use was associated with higher esophageal dysmotility disorders, including distal esophageal spasm (pooled OR 4.84, 95% CI 1.60-14.63, P = 0.005, I 2 = 96%), esophagogastric junction outflow obstruction (pooled OR 5.13, 95% CI 2.11-12.43, P = 0.0003, I 2 = 93%), and type III achalasia (pooled OR 4.15, 95% CI 2.15-8.03, P < 0.0001, I 2 = 64%). No significant differences were observed for hypercontractile esophagus, type I achalasia, or type II achalasia. The basal lower esophageal sphincter pressure (MD 3.02, 95% CI 1.55-4.50, P < 0.0001, I 2 = 90%), integrated relaxation pressure (MD 2.51, 95% CI 1.56-3.46, P < 0.00001, I 2 = 99%), and distal contractile integral (MD 640.29, 95% CI 469.56-811.03, P < 0.00001, I 2 = 91%) significantly differed between the opioid use and nonopioid use group. However, opioid use was associated with a lower risk of ineffective esophageal motility (pooled OR 0.68, 95% CI 0.49-0.95, P = 0.02, I 2 = 53%).

DISCUSSION

Chronic opioid exposure is associated with an increased frequency esophageal dysmotility disorders. Our results revealed that opioid use is significantly associated with type III achalasia but not with type I and II achalasia. Therefore, opioid treatment should be taken into account as a potential underlying risk factor when diagnosing these major esophageal motor abnormalities.

[Esophageal Motility Disorders - What's New?]

Esophageal motor disorders are an important cause of dysphagia but can also be associated with retrosternal pain and heartburn as well as regurgitation. In extreme cases, patients are not able to eat appropriately and lose weight. Repetitive aspiration can occur and may cause pulmonological complications. Achalasia represents the most important and best-defined esophageal motor disorder and is characterized by insufficient relaxation of the lower esophageal sphincter in combination with typical disturbances of esophageal peristalsis. Additional defined motor disorders are distal esophageal spasm, hypercontractile esophagus, absent contractility and ineffective peristalsis. Patients with appropriate symptoms should primarily undergo esophagogastroduodenoscopy for exclusion of e.g., tumors and esophagitis. Esophageal high-resolution manometry is the reference method for diagnosis and characterization of motor disorders in non-obstructive dysphagia. An esophagogram with barium swallow may deliver complementary information or may be used if manometry is not available. Balloon dilatation and Heller myotomy are long established and more or less equally effective therapeutic options for patients with achalasia. Peroral endoscopic myotomy (POEM) enhances the therapeutic armamentarium for achalasia and hypertensive/spastic motor disorders since 2010. For hypotensive motor disorders, which may occur as a complication of e.g., rheumatological diseases or idiopathically, therapeutic options are still limited.

Chronic opioid use is associated with obstructive and spastic disorders in the esophagus

BACKGROUND AND AIMS

Chronic opioid effects on the esophagus are poorly understood. We investigated whether opioids were associated with increased prevalence of esophageal motility disorders.

METHODS

A retrospective study of all patients undergoing high-resolution manometry (HREM) at the Yale Gastrointestinal Motility Lab between January 2014 and August 2019. Data were extracted from the electronic medical record after studies were reviewed by two motility specialists using the Chicago Classification v.3.0. We compared the manometric results of patients who use opioids to those who do not and adjusted for type and dose of opioids using a 24 h Morphine Milligram Equivalents (MME) scale to compare patients taking low or high amounts of opioids.

RESULTS

Four manometric abnormalities were significantly different between the opioid and non-opioid users. Achalasia type III, esophagogastric junction outflow obstruction (EGJOO), and distal esophageal spasm (DES) (p < 0.005, p < 0.01, and p < 0.005, respectively) were common among opioid users, whereas ineffective esophageal motility (IEM) was more common among non-opioid users (p < 0.01). The incidence of EGJOO was significantly higher in opioid users compared to non-opioid users (p < 0.001). Lastly, IRP, DCI, and distal latency were significantly different between the two groups. Patients in the high MME group had significantly greater IRP, DCI, and lower distal latency than non-opioids (p < 0.001). Also, achalasia type III and DES were more common in the high but not the low MME group.

CONCLUSIONS

Opioid use is associated with multiple abnormalities on esophageal motility and these effects may be dose-dependent.

Effects of remifentanil on pharyngeal swallowing and esophageal motility: no impact of different bolus volumes and partial antagonism by methylnaltrexone

Remifentanil impairs swallowing, and disturbed accommodation to bolus volume may be one of the underlying causes. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. So, this study aimed to investigate if remifentanil-induced swallowing dysfunction is dependent on the bolus volume and whether the effect of remifentanil could be counteracted by methylnaltrexone, a peripherally acting opioid antagonist. Nineteen healthy volunteers were included in this double-blinded, randomized, placebo-controlled, crossover study. Study participants received target-controlled remifentanil infusions and placebo infusions in a randomized order. Methylnaltrexone was administered by intravenous injection of doses of 0.3 mg/kg. Recordings of pressure and impedance data were acquired using a combined manometry and impedance solid-state catheter. Data were analyzed from three series of bolus swallows, baseline, during study medication exposure, and 15 min after methylnaltrexone. Remifentanil induced significant effects on multiple pharyngeal and esophageal function parameters. No significant differences in remifentanil-induced swallowing dysfunction related to different bolus volumes were found. Pharyngeal effects of remifentanil were not significantly counteracted by methylnaltrexone, whereas on the distal esophageal level, effects on distension pressures were counteracted. Changes in pharyngeal and esophageal pressure flow variables were consistent with previous results on remifentanil-induced swallowing dysfunction and uniform across all bolus volumes. The effects of remifentanil on the pharyngeal level and on the proximal esophagus appear to be predominantly centrally mediated, whereas the effects of remifentanil on the distal esophagus may be mediated by both central and peripheral mechanisms.NEW & NOTEWORTHY In this randomized controlled trial, we used the "Swallow Gateway" online platform to analyze the effects of remifentanil on pharyngeal and esophageal swallowing. It is not fully understood whether remifentanil-induced swallowing dysfunction is mediated by peripheral or central mechanisms. By using methylnaltrexone, we demonstrated that effects of remifentanil on pharyngeal swallowing were predominantly centrally mediated, whereas its effects on the distal esophagus may be mediated by both central and peripheral mechanisms.