<prompt> Which of the following conditions increases the risk of digoxin toxicity?Administration of quinidineHyperkalemiaHypermagnesemiaHypocalcemia  <response>: Quinidine: Reduces binding of digoxin to tissue proteins as well as its renal and biliary clearance by inhibiting efflux transpoer P-glycoprotein - plasma concentration of digoxin is doubled - toxicity can occur. Decreased levels of serum potassium hypokalemia predispose a patient to digoxin toxicity, because it competes with potassium for NaK-ATPase pump. Patients receiving thiazide or loop diuretics may be prone to hypokalemia Severe toxicity resulting in Ventricular tachycardia may require administration of antiarrhythmic drugs Lignocaine and the use of digibind 