Low-dose carvedilol is considered a potent portal hypotensive pharmacological agent, say British researchers.
Doctors at the Liver Unit at the Royal Infirmary of Edinburgh, in Scotland assessed the haemodynamic effects and patient tolerability of acute and chronic administration of low -dose carvedilol following recent studies demonstrating its potential as a portal hypotensive agent. The drug is a non-selective vasodilating b-blocker with weak a 1 receptor antagonism.
Ten patients with cirrhosis and portal hypertension were enrolled into the study. Haemodynamic measurements were undertaken before, and one hour following administration of oral carvedilol, 12.5 mg. This was repeated four weeks later.
A reduction of 23 percent was identified in the hepatic venous pressure gradient following acute administration of carvedilol. These ranged from 16.37 ± 2.14 to 12.56 ± 3.91 mmHg (P< 0.05). There was also a notable fall in the heart rate, mean arterial pressure and cardiac output.
A further fall in the hepatic venous pressure gradient was established following chronic administration. This was from a baseline of 16.37 ± 0.71 to 9.27 ± 1.40 mmHg (P<0.001), with no effect on the mean arterial pressure. Only one patient experienced asymptomatic hypotension otherwise carvedilol was well tolerated.