Gut Motility and Transit Changes in Patients Receiving Long‐Term Methadone Maintenance

Abstract

This study was conducted to survey gut motility and transit in 19 volunteers receiving methadone maintenance who were opioid‐dependent, and to measure the oral‐cecal transit time in these individuals using the lactulose hydrogen breath test. None of these patients reported constipation problems before use of illicit drugs. During current long‐term methadone therapy, 58% of patients experienced some degree of constipation, and two of these 19 patients reported that constipation was a very serious problem. Mean ± standard deviation (SD) oral‐cecal transit time in these individuals was 159 ± 49.2 minutes, which is significantly longer than the transit time recorded in two previous studies of healthy volunteers (P < 0.01). These results indicate that tolerance to opioids does not appear to extend to gastrointestinal motility and transit. It seems that patients receiving long‐term methadone therapy are a good model for use in evaluating gastrointestinal effects of opioid antagonists.