Renal and humoral effects of ibopamine, a dopamine agonist, in patients with liver cirrhosis

We investigated the renal and humoral effects of short-term administration of ibopamine, an orally active dopamine agonist, in patients with liver cirrhosis. The patients were divided into two groups on the basis of sodium excretion with a constant sodium intake of 40 mEq/d. We also compared the effects of ibopamine with those induced by intravenous infusion of dopamine hydrochloride (3 μg/kg per minute) in similar patients. Ibopamine caused significant increases in urine output, glomerular filtration rate, and sodium excretion throughout the 4 hours of the trial in patients with basal sodium excretion rate greater than 20 mmol/d. These renal effects were associated with a significant reduction in plasma aldosterone concentration. In contrast, only a transient increase in glomerular filtration and a dilution in plasma aldosterone concentration were observed after ibopamine in the patients with a basal sodium excretion rate less than 20 mmol/d. The infusion of dopamine had renal effects similar to those of ibopamine in both groups of patients. These results indicate that in cirrhotic patients with normal sodium excretion, ibopamine exerts a diuretic and natriuretic effect similar to that of dopamine infusion. However, these properties of dopaminergic agents are apparently lost in patients with avid sodium retention.