A double-blind, controlled trial to study the efficacy of acidifying enemas of lactitol, a new galactoside-sorbitol disaccharide, and lactose vs. nonacidifying tap-water enemas was performed in 45 episodes of acute portal-systemic encephalopathy. At the time of randomization, all patients had encephalopathy of at least Grade 2+ severity, delay in the performance of number connection tests and hyperammonemia. A sequential analysis was performed which revealed after the inclusion of the first 20 patients, a significant failure of the nonacidifying enemas as compared to the lactitol enemas (p less than 0.004). The tap-water enema group was, therefore, suspended but the rest of the study continued after rerandomization for lactose and lactitol groups. A favorable response to treatment was obtained in 19 (86%) of the patients receiving lactitol enemas and in 14 (78%) of those receiving lactose enemas. A similar significant improvement in portal-systemic encephalopathy parameters and index was observed after both treatments. Both types of acidifying enemas induced a significant pH decrease in stool (p less than 0.05). These data suggest that acidifying agents like lactose and lactitol are effective and superior to tap-water enemas for the treatment of acute nitrogenous portal-systemic encephalopathy.

A double-blind crossover trial was performed to test the therapeutic usefulness and safety of lactitol, a beta-galactoside sorbitol, against lactose in 18 patients with chronic portal-systemic encephalopathy (PSE). The study included four periods: two for washout and two for lactitol and lactose administration. During washout periods, which lasted two weeks each, patients were stabilized with neomycin plus milk of magnesia. Lactitol and lactose were administered during four weeks each. Ten patients were randomly assigned to receive lactose (group A) and eight patients to receive lactitol (group B) first. PSE parameters, ie, mental state, number connection test performance, asterixis and blood ammonia levels were assessed fortnightly. Electroencephalographic tracings and stool pHs were evaluated at the end of each study period. After the first administration of lactose and lactitol, no statistically significant differences in PSE parameters were found. At the same stage, a significant stool acidification (P<0.05) was detected. It is concluded that lactitol seems to be safe and efficacious in treating patients with chronic PSE.