Rifaximin, a non-absorbable rifamycin, for the treatment of hepatic encephalopathy. A double-blind, randomised trial.

The aim of this study was to evaluate the efficacy and tolerability of rifaximin, a non-absorbable intestinal antibiotic, in comparison to neomycin in the short- and long-term treatment of hepatic encephalopathy (HE). Forty-nine patients with a definite diagnosis of cirrhosis were included in this double-blind, randomised, controlled trial. Patients were randomly assigned to one of the following treatments: (1) rifaximin 400 mg three times daily; (2) neomycin 1 g three times daily. Both drugs were administrated orally as tablets during 14 consecutive days each month, for a period of six months. The neuropsychiatric signs and blood ammonia levels were examined before starting the treatment, and every 30 days, until the final assessment. In all patients a progressive and important reduction in HE grade was observed, and no statistically significant difference between the two treatments was detected. In both groups the disturbances in speech, memory, behaviour and mood, gait, asterixis, writing, and serial subtraction of 7 s and five-pointed star tests all showed the highest proportion of improvement. During the study blood ammonia levels decreased in both the rifaximin and in the neomycin groups, and again no statistically significant difference was found between groups. Our findings confirm, therefore, the usefulness of rifaximin in the treatment of HE, supporting its use as a first-choice antibiotic, particularly in patients intolerant to neomycin or with impaired renal function.