The pharmacokinetics of metoclopramide has been studied after acute IV administration to 12 patients with hepatic cirrhosis (6 with and 6 without ascites) and 6 control subjects. The elimination half-life was significantly longer in patients (11.4 h and 9.9 h in those with and without ascites, respectively, vs 6.4 h in controls). Total plasma clearance was significantly lower in patients (0.29 and 0.36 l.kg-1.h-1 vs 0.52 l.kg-1.h-1 in controls). The differences between patients with and without ascites did not reach statistical significance. Reduction of functional hepatic blood flow in cirrhotic patients is the probable cause of the observed alteration in metoclopramide kinetics.