The effect of levomoprolol on portal hemodynamics in rats: comparison with propanolol

Pharmacological therapy with propranolol represents an interesting trend in the prevention of hemorrhagic relapses from esophageal varices. Nevertheless, the limited use of propranolol in only a small number of selected patients with portal hypertension, and its side effects on the cardiovascular, nervous and respiratory systems, call for alternative beta blockers to be tested. Beta1 cardioselective blockers, such as atenolol and metoprolol, have not achieved the desired results in either hemodynamic or clinical trials. The purpose of this investigation was to compare the effects on portal hemodynamics of propranolol and levomoprolol (Levotensin-1 Simes) in normal rats. This is a new hydrophilic and levo-rotatory beta blocker. The hemodynamic results obtained by the two drugs are similar as regards both the reduction of portal flow (24% after administration of levomoprolol and 20% after propranolol) and decrease in portal pressure (30% after levomoprolol and 20% after propranolol). However, the bradycardia induced in the rat by levomoprolol is significantly less marked than that induced by propranolol. A statistically significant reduction of cardiovascular side effects and lower dosage requirements indicate that the study on levomoprolol should also be extended to the clinical field.