12 patients with cirrhosis of the liver (6 with ascites) and 6 control persons were given 80 mg furosemide intravenously and were followed up for pharmacokinetic, renal and haemodynamic effects. The patients with ascitic cirrhosis (AC) and the control persons were found to have the same plasma furosemide concentrations; however, the AC patients excreted significantly less furosemide into the urine in an 8-hour period than the control persons, which was due especially to lower urine furosemide excretion during the first hour after application in comparison with the control group (75 +/- 6.8 vs. 100.8 +/- 8.8 mumol/h, p less than 0.05). During the first post-furosemide hour, the AC patients had a significantly lower diuresis (13.3 +/- 2.4 vs. 23.9 +/- 1.1 ml/min, p less than 0.01) as well as natriuresis (1367.4 +/- 771.4 vs. 3242 +/- 137.5 mumol/min, p less than 0.01) than the control group and a significantly lower excretion fraction of sodium than the patients with live cirrhosis without ascites (6.5 +/- 0.8 vs. 10.7 +/- 1.5%, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)