Lactulose in cirrhosis: Current understanding of efficacy, mechanism, and practical considerations.

HE is a complication of cirrhosis characterized by neuropsychiatric and motor dysfunction, and results in decreased quality of life and increased mortality. Lactulose is a synthetic disaccharide used to treat HE since 1966, though many questions about its use remain unanswered. Lactulose reverses minimal HE, prevents overt HE, improves quality of life, increases the rate of recovery from overt HE, and improves survival rates. Lactulose's clinical effect appears to be derived from its impact on intestinal microbes, likely a result of its enteric acidifying effect, positive pressure on beneficial taxa, and improvement of gut barrier function. There are several practical considerations with lactulose including (1) a need to avoid excessive bowel movements and subsequent dehydration, (2) treatment titration protocols need further investigation, (3) baseline or treatment-induced gastrointestinal side effects limit adherence in some cases, and (4) the utility of monitoring stool consistency or pH remains unknown. Further research is needed to optimize our use of this effective treatment for HE.