Lactitol in the treatment of chronic hepatic encephalopathy: an open comparison with lactulose.

Lactulose is currently the drug of choice for the treatment of hepatic encephalopathy. It is, however, only available as a syrup which is contaminated with other sugars. Consequently patients may express aversion to its excessively sweet taste and many experience nausea because of its hyperosmolarity. Lactitol is a disaccharide analogue of lactulose which can be produced as a pure crystalline powder with a low relative sweetness. Theoretically it should have the same therapeutic effects as lactulose but fewer side effects. Five patients with chronic hepatic encephalopathy on maintenance lactulose were monitored clinically, psychometrically, and by measurement of venous blood ammonia, electroencephalogram mean cycle frequency, and cerebral blood flow during three months treatment with lactulose and a similar period on lactitol. Lactitol was at least as efficacious as lactulose but was more acceptable because its cathartic effect was more predictable, its formulation was more convenient and its less sweet taste preferred. Lactitol is the ideal successor to lactulose for treatment of this condition.