Hypersensitivity to norepinephrine (noradrenaline) or any of the excipients.
Halothane anesthetics increase cardiac autonomic irritability and therefore seem to sensitize the myocardium to the action of intravenously administered epinephrine or noradrenaline. Hence, the use of LEVOPHED during halothane anesthesia is generally considered contraindicated because of the risk of producing ventricular tachycardia or fibrillation.