Which vasopressor should be avoided in patients taking non-selective tricyclic antidepressants?

Levonordefrin should be avoided in patients taking non-selective tricyclic antidepressants due to the potential for increased cardiovascular effects. Non-selective tricyclic antidepressants can inhibit the reuptake of norepinephrine, leading to increased blood pressure and heart rate when combined with vasopressors like levonordefrin. This interaction can cause potentially dangerous cardiovascular side effects, including arrhythmias and hypertension, due to the additive effects on adrenergic receptors.

While other options like norepinephrine, ephedrine, and phenylephrine also have vasopressor effects, levonordefrin's specific mechanism of action and its interaction profile with tricyclic antidepressants makes it a particular concern. It primarily works through both alpha and beta adrenergic receptors, and the heightened norepinephrine levels due to the antidepressants can exacerbate these actions. Therefore, healthcare providers exercise caution and typically recommend alternative vasopressors for patients on this type of medication to avoid adverse reactions.