Dilated bile duct in patients receiving narcotic substitution - An early report

Narcotic substitution is now widely used. Morphine can induce a spasm of th e sphincter of Oddi but dilation of bile duct has been reported only in an anecdotal case. In June 1995, we observed a first case of dilation of the c ommon bile duct without organic obstacle in a hepatitis C virus (HCV)-infec ted patient who was under narcotic substitution, suggesting a causal relati onship. We conducted a prospective study to evaluate the precise prevalence of bile duct abnormalities related to narcotic substitution in active intr avenous drug or ex-intravenous drug users referred to our liver unit for hi stologic evaluation of HCV infection. We conducted a prospective study in a 30-month period of 334 HCV-infected patients, including 36 receiving narco tic substitution with methadone or buprenorphine. Biliary tract was analyze d by ultrasonography and by endoscopy ultrasound in cases of bile duct abno rmalities. Of the 36 patients under narcotic substitution, 3 (8.3%) had asy mptomatic dilated bile duct without organic obstacle-defined as a common bi le duct greater than or equal to 9 mm-compared to 1 of 298 (0.03%; p < 0.00 1) of those who did not receive substitution. Narcotic substitution may lea d to bile duct dilation that does not require invasive diagnosis procedures .