In rabbits, landiolol, a new ultra-short-acting beta-blocker, exerts a more potent negative chronotropic effect and less effect on blood pressure than esmolol

Purpose: To compare the cardiovascular and sympathetic effects of a new ult ra-short-acting, highly cardioselective beta -blocker, landiolol, with esmo lol, using an in vivo rabbit model. Methods: Different bolus doses of landiolol (0.3, 1.0, 3.0 and 10.0 mg.kg(- 1)) or esmolol (0.5, 1.5 and 5.0 mg.kg(-1)) were given intravenously, and t he effects on heart rate (HR) mean arterial pressure (MAP) and renal sympat hetic nerve activity (RSNA) were compared. Results: Both landiolol and esmolol produced a dose-dependent decrease in H R. The maximum percent reductions of HR were similar with landiolol 3 mg.kg (-1) and esmolol 5 mg.kg(-1) (-14.0 +/- 0.9% and -13.9 +/- 1.4%, mean +/- S E, respectively), HR decreased more rapidly with landiolol than with esmolo l. Esmolol produced a dose-dependent decrease in MAP that was not observed with landiolol. The percent maximum reduction of MAP was -38.2 +/- 3.2% wit h esmolol 5 mg.kg(-1). RSNA increased in a close-dependent fashion with esm olol, but no changes were noted with landiolol. Conclusion: These results suggest that, in rabbits, landiolol has slightly more potent negative chronotropic action than esmolol with significantly le ss effects on blood pressure.