<p>Administration of Ephedrine may cause a hypertensive crisis in patients receiving an Monoamine Oxidase Inhibitor (including an Reversible Inhibitor of Monoamine Oxidase type A). Ephedrine should be avoided or used with care in patients undergoing anaesthesia with cyclopropane, halothane, or other volatile anaesthetics. An increased risk of arrhythmias may occur if given to patients receiving cardiac glycosides, quinidine, or tricyclic antidepressants, and there is an increased risk of vasoconstrictor or pressor effects in patients receiving ergot alkaloids or oxytocin</p>