Objectives: Dilatation of the common bile duct (CBD) can be an ominous sign for malignancy of the pancreatobiliary tract; however, it has also been described as a presumably harmless side effect of opioid use. We investigated the prevalence and determinants of CBD dilatation among drug users receiving methadone maintenance therapy in the Netherlands.
Methods: A cross-sectional study was conducted in a prospectively studied and well-defined cohort of drug users with chronic hepatitis C virus infection, attending the Public Health Service of Amsterdam, the Netherlands. Patients underwent abdominal ultrasonography as part of pretreatment screening. A multivariable logistic regression model was used to analyze potential demographic and drug use–related determinants of radiological CBD dilatation.
Results: Between September 2004 and December 2011, 222 hepatitis C virus–infected drug users were evaluated. Dilatation of the CBD was found in 50 of 222 patients (22.5%), with a median diameter of 8.0 mm (interquartile range, 7.0 to 10.0; n = 43). Dilatation was associated with current use of methadone (adjusted odds ratio = 20.50; 95% confidence interval, 2.79 to 2.61 × 103), independent of the current methadone dose, and with age per 10-year increase (adjusted odds ratio = 1.68; 95% confidence interval, 1.06 to 2.71). Regular use of heroin in the 6 months before ultrasonography was not found to be associated with dilatation.
Conclusions: Dilatation of the CBD is common in drug users under methadone treatment and seems to be a harmless side effect of opioid agonists.