Incidence of opioid-induced esophageal dysfunction.

Background: Retrospective studies have suggested that long-term use of opioids can cause esophageal motility dysfunction. A recent clinical entity known as opioid-induced esophageal dysfunction (OIED) has been postulated. There is no data from prospective studies assessing the incidence of opioid-induced effects on the esophagus.

Aim: Evaluate the incidence of OIED during chronic opioid therapy.

Methods: From February 2017 to August 2018, all patients seen in the Pain Unit of the hospital, who started opioid treatment for chronic non-neoplastic pain and who did not present esophageal symptoms previously, were included. The presence of esophageal symptoms was assessed using the Eckardt score after 3 months and 1 year since the start of the study. In February 2021, the clinical records of all included patients were reviewed to assess whether esophageal symptoms were present and whether opioid therapy was continued. In patients presenting with esophageal symptoms, an endoscopy was performed and, if normal, a high-resolution esophageal manometry was performed. For a confidence level of 95%, a 4% margin of error and an estimated prevalence of 4%, a sample size of 92 patients was calculated.

Results: 100 patients were included and followed while taking opioids, for a median of 31 months with a range between 4 and 48 months. Three women presented with dysphagia during the first 3 months of treatment, being diagnosed with esophagogastric junction outflow obstruction; type II and type III achalasia. The cumulative incidence of OIED was 3%; 95%-CI: 0-6%.

Conclusions: Chronic opioid therapy in patients with chronic non-neoplastic pain is associated with symptomatic esophageal dysfunction.