Cyclopropane and halothane anesthetics increase cardiac autonomic irritability and therefore seem to sensitize the myocardium to the action of IV administered epinephrine or norepinephrine. Hence, the use of norepinephrine during cyclopropane and halothane anesthesia is generally considered contraindicated because of the risk of producing ventricular tachycardia or fibrillation. The same type of cardiac arrhythmias may result from the use of norepinephrine in patients with profound hypoxia or hypercarbia.
Extreme caution should be exercised in patients receiving monoamine oxidase inhibitors (MAOIs) or antidepressants of the triptyline or imipramine types (see Warnings) because severe, prolonged hypertension may result.
Incompatibilities: Levophed SF solutions should not be mixed with other medicines. Infusion solutions containing noradrenaline acid tartrate have been reported to be incompatible with alkalis and oxidizing agents, barbiturates, chlorpheniramine, chlorothiazide, nitrofurantoin, phenytoin, sodium bicarbonate, sodium iodide, streptomycin, sulfadiazine and sulfafurazole.