A prospective randomized double-blind study was conducted to evaluate the efficacy of
sodium benzoate in the treatment of acute
portal-systemic encephalopathy. Seventy-four consecutive patients with
cirrhosis or surgical portasystemic anastomosis and
hepatic encephalopathy of less than 7 days duration were randomized to receive
lactulose (dose adjusted for 2 or 3 semiformed stools/day) or
sodium benzoate (5 gm twice daily). Assessment of response included mental status,
asterixis, arterial
ammonia level, electroencephalogram and number-connection test. Each was given a score between 0 and 4+. A
portal-systemic encephalopathy index was calculated with these scores. Visual, auditory and somatosensory evoked potentials and a battery of psychometric tests for intelligence and memory were also performed to assess improvement. Thirty-eight patients received
sodium benzoate; 36 took
lactulose. Thirty patients (80%) receiving
sodium benzoate and 29 (81%) receiving
lactulose recovered; the remaining patients died. Improvement in
portal-systemic encephalopathy parameters occurred in both treatment groups and was similar (p greater than 0.1). Electroencephalogram and evoked potentials were not as helpful as mental status in assessing of recovery. Psychometric test scores remained abnormal after recovery of mental status (21 to 42 days) and were probably too sensitive for monitoring of these patients. The incidence of side effects was similar in the two treatment groups. The cost of
lactulose for one course of
therapy was 30 times that of
sodium benzoate. We conclude that
sodium benzoate is a safe and effective alternative to
lactulose in the treatment of acute portasystemic
encephalopathy.