Warnings or dangers associated with MAOIs:
When taken orally, MAOIs inhibit the metabolic breakdown of dietary amines. Sufficient intestinal inhibition can lead to hypertensive crisis when foods containing tyramine are consumed or hyperserotonemia (elevated serotonin levels) if foods containing tryptophan are consumed. Tyramine is a building block of norepinephrine, and is commonly found in foods such as chocolate, alcoholic beverages, Chianti and other aged wines, fish, and fermented foods such as sauerkraut, meat and yeast extracts, soy sauce, aged cheese, soy bean condiments, and processed meat.
MAOIs inhibit monoamine oxidase and so the body cannot rid itself of excess norepinephrine. Raised levels of norepinephrine may lead to a hypertensive crisis and even cause intracerebral hemorrhage and death after the consumption of certain types of tyramine-containing foods or drinks. Hypertensive crises sometimes result in stroke or cardiac arrhythmia if left untreated.
Combined use of non-selective MAO inhibitors and serotonergic drugs (SSRIs, MDMA, or other phenylethylamines) is likely to lead to serotonin syndrome, a rare but serious and potentially life-threatening hyperserotonergic medical condition. Serotonin syndrome can also occur when combining MAOIs with certain opiods like Meperidine. MAOIs may not be combined with other antidepressants, most notably tricyclics, as this too may result in hypertensive crisis.