Effect of clonidine on liver oxygen extraction during alcohol withdrawal in man

Since catecholamines can alter splanchnic oxygen transport and extraction, the suppression of sympathetic overactivity during alcohol withdrawal might improve hepatic oxygen extraction. Therefore, this study investigated the effects of clonidine, a centrally-acting α 2 -agonist which reduces sympathetic nervous outflow, on splanchnic oxygen transport and extraction in 13 patients with chronic alcoholism during alcohol withdrawal. All patients had elevated transaminases and steatosis at liver biopsy and were withdrawn from alcohol 51±15 h (mean±SD) before the study. Hepatic blood flow, cardiac output and the oxygen contents were measured in the radial and pulmonary arteries and in the hepatic veins before and 45 min after intravenous administration of clonidine, 150 μ g. Basal hepatic blood flow was inversely correlated with norepinephrine plasma concentrations (r=−0.63, p p p p p