Addictive Potential: Medium
Emergency Room Visits Yearly: Unknown
Mandatory Minimum Sentence: None
Mechanism of Action: monoamine oxidase inhibitors
Monoamine oxidase inhibitors (MAOIs) are a class of powerful antidepressant drugs prescribed for the treatment of depression. They are particularly effective in treating atypical depression, and have also shown efficacy in smoking cessation. Due to potentially lethal dietary and drug interactions, MAOIs had been reserved as a last line of defense, used only when other classes of antidepressant drugs (for example selective serotonin reuptake inhibitors and tricyclic antidepressants) have failed.
MAOIs (in the form of natural, plant based beta-carbolines) are also used in the entheogen ayahuasca. In South America two churches, the Santo Daime and União do Vegetal, use ayahuasca, or hoasca, as their sacrament. This is a tea made from boiled plants. One plant contains DMT and another plant contains MAOIs, or monoamine oxidase inhibitors. DMT is only orally active when it is combined with an MAOI.
MAOIs Commonly Used in Ayahuasca:
Traditional: Banisteriopsis caapi
Ayahuasca Analogs: Syrian Rue (Peganum harmala/MAOI-A), Passion flower (Mild)
Pharmahuasca: Moclobemide (MAOI-A)
Side Effects and Adverse Reactions:
When ingested orally, MAOIs inhibit the catabolism of dietary amines. Sufficient intestinal MAO-A inhibition can lead to hypertensive crisis, when foods containing tyramine are consumed (so-called “cheese syndrome”), or hyperserotonemia if foods containing tryptophan are consumed. The amount required to cause a reaction exhibits great individual variation and depends on the degree of inhibition, which in turn depends on dosage and selectivity.
The exact mechanism by which tyramine causes a hypertensive reaction is not well understood, but it is assumed that tyramine displaces norepinephrine from the storage vesicles. This may trigger a cascade in which excessive amounts of norepinephrine can lead to a hypertensive crisis. Another theory suggests that proliferation and accumulation of catecholamines causes hypertensive crises.