<prompt> Which of the following is true about DigoxinIt acts by inhibiting PDE 3Dose reduction is not required in liver failureHyperkalemia predisposes to Digoxin toxicityAtrial flutter is the most characteristic arrhythmia caused by Digoxin toxicity  <response>: Digoxin acts by inhibiting Na- K ATPase.Dose reduction is required in renal failure not liver failure.Hypokalemia increases the risk of Digoxin toxicity.Most common arrhythmia in Digoxin toxicity is most ventricular bigeminy.Most characteristic arrhythmia seen in Digoxin toxicity is Atrial tachycardia AV Nodal blockade. 