Esophageal Dysfunction among Two Groups of Opioid Users

Researchers who studied side effects of chronic opioid use found esophageal dysfunction in current and chronic users, according to results of a study presented during poster sessions at the 2013 American College of Gastroenterology annual meeting in San Diego, CA.

Shiva Ratuapli, MD, and colleagues undertook the study at the Mayo Clinic in Arizona in part because while many studies have been conducted on the side effects of stomach and intestines associated with opioid use, data on the side effects of opioid use and esophageal dysfunction is limited.

The researchers set out to compare high-resolution esophageal pressure topography (EPT) of patients who took opioids at the time of the EPT (= 24 hours) with chronic opioid users who had not taken opioid medications for at least 24 hours. To characterize esophageal dysmotility, they used the Chicago classification, an algorithmic scheme used for diagnosis.

The 123 opioid users identified from the motility database underwent high-resolution EPT from March 2010 to August 2012. Researchers compared demographics along with data from high-resolution manometry, which measures muscle contractions and patterns of the esophagus, between the two groups using General Linear Models or chi-square.

Of those studied, 67 patients were current opioid users and 56 had not used opioids in the past 24 hours. In 46 percent of those using opioids, the last dose was taken within 4 hours of manometry. For patients who were off opioids, the last dose ranged from 2 days to 186 days.

Outflow obstruction was observed more often in patients using opioids within 24 hours compared to those who did not. Other measures of esophageal motor function tended to be more frequent or higher when opioids were used, such as the distal esophageal spasm (more frequent) and the distal contractile interval and resting lower esophageal sphincter (LES) pressures (higher). The mean LES residual pressure was significantly higher among those patients on opioids (10.54 versus 6.70 mmHg, P=0.034).

Data also showed that subtype III criteria for achalasia, a disorder of the esophagus, were met more frequently in patients studied on opioids (10.4 percent versus 0.0 percent, P=0.016). Other Chicago classifications were similar in prevalence in the groups.

Researchers concluded that both chronic and current opioid users experienced induced esophageal dysfunction. Outflow obstruction and spastic esophageal dysmotility patterns were more frequent among those who took opioids within 24 hours of manometry compared with opioid users who stopped opioid for at least 24 hours before the study began.