Which MAOI is most commonly associated with dietary restrictions involving tyramine?

Phenelzine is most commonly associated with dietary restrictions involving tyramine due to its mechanism of action as a monoamine oxidase inhibitor (MAOI). This medication irreversibly inhibits the monoamine oxidase enzyme, which is responsible for breaking down neurotransmitters such as norepinephrine, serotonin, and dopamine. Because of this inhibition, the intake of foods containing tyramine can lead to excessive levels of norepinephrine, resulting in hypertensive crises.

Patients taking phenelzine must adhere to a strict diet avoiding tyramine-rich foods, such as aged cheeses, cured meats, and fermented products, to prevent potentially dangerous interactions. While other MAOIs like tranylcypromine and isocarboxazid also require some dietary consideration regarding tyramine, phenelzine's association with these dietary restrictions is particularly emphasized in clinical practice. Selegiline, especially in lower doses, can be less restrictive when administered as a transdermal patch due to its lower risk of tyramine interaction in that form, further differentiating it from phenelzine.