The combination of MAO inhibitors such as some ayahuasca j carbolines
with monoaminergic and serotoninergic substances in general, antidepressives, as well as ginseng, St John's wort, dextromethorphan, amphetamine, and 3,4-methylenedioxymethamphetamine (MDMA: "ecstasy"), could produce the serotonin syndrome (dos Santos 2013a; Pilgrim et al.
Acetaldehyde also may condense with serotonin to form compounds called tetrahydro-beta carbolines
that may be active in the brain as well.
Of chief importance is the pan Amazonian hallucinogenic brew Ayahuasca, which is a preparation containing Beta carboline
alkaloids (viz.Harmine, Harmaline and tetrahydroharmine, which act as MAOIs) contained in the vine Banisteriopsis caapi , which is boiled with the leafs of DMT containing plants, commonly used are Psychotria viridis, P.
Inhibition of human cytochrome P450 enzymes 3A4 and 2D6 by p carboline
alkaloids, harmine derivatives.