Portal venous flow in response to acute β-blocker and vasodilatatory treatment in patients with liver cirrhosis

Abstract

The drugs currently under investigation in the prevention of recurrent gastrointestinal bleeding in cirrhosis are likely to decrease the portal pressure by means of a primary reduction of portal blood flow. The hemodynamic effects of β-blocking agents and vasodilatory drugs were noninvasively measured in eight patients with cirrhosis by means of pulsed echo-doppler equipment. Portal caliber, blood velocity and flow were recorded hourly after a single dose of propranolol (40 mg p.o.) or atenolol (100 mg p.o.), and every 5 min after treatment with isosorbide dinitrate (5 mg sublingually). The drugs were administered at random with an interval of 2 days or more. The portal caliber decreased after atenolol, but did not change after propranolol and isosorbide. The blood velocity decreased by 29 ± 2% 3 hr after propranolol, by 26 ± 2% 3 hr after atenolol and by 31 ± 3% 15 min after isosorbide. The portal blood flow decreased by 0.29 ± 0.03 liters per min after propranolol, by 0.34 ± 0.06 after atenolol and by 0.26 ± 0.03 after isosorbide, without any difference among the various treatments. β-blockers and vasodilatory drugs have comparable effects on portal blood flow. β₁-selective and nonselective β-blockers are similarly effective in keeping with the hypothesis that changes in portal blood flow are mainly due to the block of β₁-receptors.