N-Epi Drug Interactions

Beta-Blockers: Beta-blockers directly antagonize the beta-agonist (i.e., cardiac-stimulating) effects of norepinephrine. Possible increased risk of severe hypertension and bradycardia when noradrenaline (norepinephrine) given with non-cardioselective beta-blockers.
Beta-Blockers: May enhance the vasopressor effect of Alpha-/Beta-Agonists (Direct-Acting).
COMT Inhibitors: Drugs known to be metabolized by catechol-O-methyltransferase (COMT), such as norepinephrine, regardless of the route of administration, should be administered cautiously in patients receiving COMT-inhibitors like entacapone or tolcapone. Concomitant use may result in increased heart rates, possibly arrhythmias, and excessive changes in blood pressure. Effects of noradrenaline (norepinephrine) possibly enhanced by entacapone.
COMT Inhibitors: May decrease the metabolism of COMT Substrates.
Risk C: Monitor therapy.
MAO Inhibitors (moderate, theoretical): May enhance the vasopressor effect of norepinephrine. Norepinephrine bitartrate injection should be used with extreme caution in patients receiving monoamine oxidase inhibitors (MAOI) because severe, prolonged hypertension may result.
Tricyclic Antidepressants: May enhance the vasopressor effect of norepinephrine. Norepinephrine bitartrate injection should be used with extreme caution in patients receiving antidepressants of the triptyline or imipramine types, because severe, prolonged hypertension may result.
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 bitartrate injection during cyclopropane and halothane anesthesia is generally considered contraindicated because of the risk of producing ventricular tachycardia or fibrillation.