<prompt> Esmolol is a short acting beta blocker because:It has more plasma protein bindingIts plasma hydrolysis by esterases is rapidIt has high lipid solubilityIt has high oral bioavailability  <response>: Ref Goodman Gillmans 13th ed. P 216-17Esmolol is a b1-selective antagonist with a rapid onset and a very short duration of action t 12 8 minutes.The drug is hydrolyzed rapidly by esterases in erythrocytes leading to its short half-life.Esmolol is used in urgent settings where immediate onset of b-blockade is warranted so it is given by slow intravenous injection.A partial loading dose 500mgkg over 1 minute typically is administered, followed by a continuous infusion of the drug maintenance dose of 50mgkgminfor 4 minutesThe lipid solubility of esmolol is low and has no oral bioavailability so it is given via IV.The protein binding of esmolol is 55. 