A critical analysis of studies assessing L-ornithine-L-aspartate (LOLA) in hepatic encephalopathy treatment.

CONTEXT Experimental and clinical studies suggest that LOLA may have a favorable influence on hepatic encephalopathy due to the effect on the reduction of ammonia, and improvement of the symptoms and laboratory findings. OBJECTIVES To evaluate and to critically analyze the efficacy and/or effectiveness results of the use of LOLA when compared to placebo in the treatment of hepatic encephalopathy. DATA SOURCES LILACS, SciELO, MEDLINE, PubMed database and Cochrane Collaboration Register of Controlled Trials were searched from 1966 to September of 2006. The review has included all the randomized controlled double-blind clinical trials performed in humans in English language. RESULTS Four studies published between 1993 and 2000 were selected and reviewed. LOLA was showed as being able to reduce hyperammonemia in patients with hepatic encephalopathy, when compared to patients in the placebo group. CONCLUSIONS Although the trials have shown efficacy of LOLA in reducing hyperammonemia of hepatic encephalopathy, sufficient evidence of a significant beneficial effect of LOLA on patients with hepatic encephalopathy was not found. The studies performed in this area were small, with short follow-up periods and half of them showed low methodological quality.