Ketamine-Induced Biliary Ductal Dilatation: A Case Report and Review of Literature

Abstract

Introduction: Ketamine is a noncompetitive NMDA receptor antagonist that is still widely used as a dissociative anesthetic agent as well as a recreational hallucinogenic drug. There is now emerging evidence that ketamine is associated with GI symptoms, abnormal liver function tests, and biliary tract abnormalities. A 19-year-old female presented with abdominal pain, hematuria, and fever for 1 day. She denied any history of drug abuse. Vital signs were within normal limits and physical revealed tenderness on the lower abdominal quadrants. Labs were significant for a ALP of 559 and ALT of 124. CT showed b/l hydroureteronephrosis as well as extra- and intrahepatic ductal dilatation up to 11 mm. Patient was started on antibiotics for UTI, and MRCP confirmed the biliary dilatation. Two unlabeled vials were found in her belongings and she admitted to using ketamine for many months.Table 1Patient progressed well and was discharged with follow-up with an addiction specialist. A literature search revealed 10 other cases with limited cases in the United States. The exact mechanism remains unknown, although it has been postulated that it is due to either direct actions on the biliary smooth muscles or central action. Studies have shown that ketamine dilates cerebral arteries by acting as a calcium antagonist. It is possible that this effect also extends to the biliary tree smooth muscle, thus causing biliary dilatation. Another hypothesis includes the dorsal motor nucleus of vagus (DMV), which has efferent fibers that project to the gallbladder. Injection of NMDA into the DMV increases gallbladder motility and its effect can be abolished following the application of ketamine in animal studies. These manifestations may be fully reversible with abstinence despite a number of the reported cases having ERCP performed. Clinicians should be aware of biliary abnormalities as a possible consequence of ketamine, especially in light of increased prevalence of ketamine abuse and its emerging role as an adjunct to opioids in cancer patients.