In patients with cirrhosis, it has been demonstrated that blood volume and degree of portal hypertension are correlated. Hence, a reduction of blood volume by furosemide could decrease portal pressure and could thereby be useful in the treatment of portal hypertension. Splanchnic and systemic haemodynamics were evaluated before and 1 h after intravenous administration of furosemide (0.75 mg/kg) in 10 patients with cirrhosis. Furosemide significantly increased haemoglobin from 12.4 to 13.0 g/dl and patients passed more than 1 l of urine within the 3 h following furosemide administration. These findings confirm that blood volume decreased after diuretic administration. Cardiac output significantly decreased from 6.6 +/- 2.3 to 5.5 +/- 2.2 l/min, while arterial pressure and heart rate did not change significantly. Furosemide significantly decreased wedged hepatic venous pressure from 31.1 +/- 6.2 to 27.7 +/- 5.2 mmHg, but not free hepatic venous pressure. Accordingly, the hepatic venous pressure gradient significantly decreased from 22.1 +/- 5.4 to 19.5 +/- 4.0 mmHg. Azygos blood flow and hepatic blood flow also significantly decreased from 0.40 +/- 0.17 to 0.31 +/- 0.13 l/min and from 1.49 +/- 0.50 to 0.82 +/- 0.30 l/min, respectively. These results show that diuretic therapy markedly influences splanchnic haemodynamics.