Improvement in hepatopulmonary syndrome after methadone withdrawal: a case report with implications for disease mechanism.

Spontaneous resolution of hepatopulmonary syndrome (HPS) without liver transplantation or improvement in the underlying liver disease has rarely been reported in the literature. Increased endogenous production of nitric oxide has been implicated in the pathogenesis of HPS. We report the case of a 50-year-old man with hepatitis C cirrhosis who demonstrated dramatic improvement in HPS after withdrawal from chronic methadone therapy. We speculate on the potential role of opiate receptors in the pulmonary vasculature and their effect on nitric oxide signaling as a potential mechanism accounting for the patient's clinical improvement.