Tu1213 – Acute Administration of Codeine Has No Effect on Motility and Bolus Flow in the Pharynx and Upper Esophageal Sphincter

Abstract

Background: Opioids, such as codeine and morphine, are a class of drugs often used in clinical practice for pain treatment. Moreover, chronic administration of opioids has shown to affect the motility of the esophagus and gastro‐intestinal tract. However, the use of opioids in acute setting and the effect on pharyngeal function have not been well documented. The aim of this study was to investigate the acute effect of opioids on pharyngeal motility and upper esophageal sphincter (UES) function during deglutition. Methods Eighteen healthy volunteers (5 males, 35 y [22‐56]) participated in a randomized, double‐blinded, placebo‐controlled, cross‐over study at University Hospital Leuven. Participants were tested on two separate occasions with a wash‐out period of at least seven days, during which placebo (30mL glucose syrup) or codeine (30 mL of codeine phosphate 10mg/5mL) was administered via a feeding tube into the stomach. After a waiting period of 75 minutes, different volumes of liquid boluses (5 mL and 20 mL), different consistencies of liquid boluses (International Dysphagia Diet Standardization Initiative (IDDSI) 0 and 4) and bread boluses (2x2cm) were given to the participants. Data collection was performed using a solid state High Resolution impedance Manometry catheter (Unisensor, Attikon, Switzerland) and analyzed using Pressure Flow Analysis (PFA) on SwallowGatewayTM online analysis platform. Six pharyngeal PFA metrics were selected as outcome measures: Swallow Risk Index, UES Maximum Admittance, Intra‐Bolus Pressure, Velopharyngeal to Tongue Base Integral, Hypopharyngeal Peak Pressure and UES Post‐relaxation Peak Pressure. Results Swallow by swallow analysis showed no significant differences in any of the PFA metrics between the codeine and placebo condition (Table 1). When comparing the bolus volume in the same condition, a higher bolus volume increased the UES admittance, representing deglutitive UES opening, in both the placebo as in the codeine condition (p<0.0001; Figure 1A). Increased bolus consistency also increased the UES admittance in both conditions (p=0.003; Figure 1B). However, no interaction effect between condition, volume and consistency was observed. Conclusion Acute intake of codeine had no significant effect on the motility and bolus flow in pharynx and the UES. However, a higher bolus volume or bolus consistency increased the UES admittance in both conditions. [Figure Presented]