Rifaximin confers cognitive benefits in covert hepatic encephalopathy

In the treatment of patients with covert hepatic encephalopathy, use of rifaximin results in improved cognitive performance and decreased cirrhosis-related adverse events, as shown in an open-label study.

The study included 50 patients with covert hepatic encephalopathy associated with liver cirrhosis. These patients were randomly assigned to receive rifaximin or no treatment for 12 weeks.

The primary endpoint was the change in Stroop test performance from baseline to week 12. Number connection test B (NCT-B) scores, serum ammonia levels, cirrhosis-related adverse events, and gut microbiota composition were also evaluated as secondary endpoints.

Over 12 weeks, Stroop test performance significantly improved among rifaximin-treated patients (p=0.006) but not among those who received no treatment (p=0.400), with the difference indicating a trend toward greater improvement with rifaximin (mean change, −4.45 vs −0.98 s; p=0.056).

In the subgroup of patients not receiving synthetic disaccharides at baseline, the improvement in Stroop test performance was significantly greater in the rifaximin group than in the control group (mean change, −3.73 vs −0.80 s; p=0.049).

There were no significant changes seen in NCT-B scores or serum ammonia levels.

Significantly fewer cirrhosis-related adverse events occurred in the rifaximin group than in the control group (p=0.006).

Overall, gut microbial diversity did not significantly differ between the two groups. However, rifaximin appeared to exert a selective influence on the microbiome, specifically involving the loss of the [Eubacterium] brachy group.