Haemodynamic effects of acute and chronic administration of low-dose carvedilol, a vasodilating beta-blocker, in patients with cirrhosis and portal hypertension.

BACKGROUND: Carvedilol is a non-selective vasodilating beta-blocker with weak alpha1 receptor antagonism. Recent studies have demonstrated its potential as a portal hypotensive agent. AIM: To assess the haemodynamic effects and patient tolerability of the acute and chronic administration of low-dose carvedilol.
METHODS: Haemodynamic measurements were performed in ten cirrhotic patients before and 1 h after the administration of 12.5 mg oral carvedilol. The study was repeated 4 weeks after daily administration of 12.5 mg carvedilol.
RESULTS: After acute administration of carvedilol, there was a 23% reduction in the hepatic venous pressure gradient from 16.37 +/- 2.14 to 12.56 +/- 3.91 mmHg (P < 0.05), with significant falls in the heart rate, mean arterial pressure and cardiac output. Chronic administration resulted in a further fall in the hepatic venous pressure gradient from a baseline of 16.37 +/- 0.71 to 9.27 +/- 1.40 mmHg (P < 0.001) with the mean arterial pressure being unaffected. The drug was well tolerated with only one patient experiencing asymptomatic hypotension.
CONCLUSIONS: The results show that low-dose carvedilol is an extremely potent portal hypotensive pharmacological agent, and is worthy of further investigation in large randomized trials to assess its effect in preventing variceal haemorrhage.