To evaluate the risk of hepatic encephalopathy and arterial hypotension in cirrhotic patients after acute administration of acamprosate, a GABA mimetic drug used in the weaned alcoholic, a randomized double-blind trial was conducted in 24 cirrhotic patients with low or moderate hepatic insufficiency (Pugh grade A or B). Twelve patients received 666 mg (2 tablets) of acamprosate and 12 received placebo. The 2 groups were similar before treatment, except for a male predominance in the acamprosate group. Tested parameters were the P100 latency of visual evoked potentials using a checkerboard pattern reversal as stimulus, the number connection test and the arterial blood pressure in upright and recumbent positions. The two first parameters were studied before and 2 hours after treatment. Blood pressure was recorded every half hour during 6 hours. No significant effect on the development of subclinical hepatic encephalopathy was noted. Nevertheless, even if some authors disagree with the GABA hypothesis of hepatic encephalopathy, it is possible that the dose was too low to induce subclinical hepatic encephalopathy. A study with more prolonged treatment could be necessary to be sure of the drug's safety in these patients. On the other hand, a transient decrease of diastolic arterial blood pressure was observed without significant systolic blood pressure modification. These results suggest that a moderate dose of acamprosate does not induce subclinical encephalopathy, but transient diastolic hypotension.