Effects of GABA-B agonist baclofen on esophageal motility: Studies using high-resolution manometry.

Background/aim: Baclofen inhibits transient lower esophageal sphincter (LES) relaxation. This study aimed to investigate the effect of baclofen on esophageal peristaltic function and contraction reserve in healthy adults using high-resolution manometry (HRM).

Methods: Fifteen subjects underwent HRM with ten water swallows and five multiple rapid swallows (MRS) 90 minutes after oral intake of either baclofen or placebo on separate days at least 1 week apart. HRM parameters assessed included esophagogastric junction contractile integral (EGJ-CI), resting LES pressure, 4-second integrated relaxation pressure (IRP-4s), distal contractile integral (DCI), distal latency, peristaltic breaks, resting upper esophageal sphincter (UES) pressure, and contractile response to MRS.

Results: Baclofen significantly increased EGJ-CI (P = .007), IRP-4s (P = .003), and LES pressure (P = .004). UES pressure, latency, and DCI were similar between baclofen and placebo (P = .87, P = .84, and P = .54, respectively). There was no difference in contractile response and peristaltic augmentation following MRS between baclofen and placebo (93% vs 100%, P = .30; 53% vs. 73%, P = .26, respectively).

Conclusions: Baclofen increases resting LES pressure and EGJ barrier function, but has no effect on primary peristalsis or contraction reserve.