You may have seen mass media advertisements for prescription drugs called “MAO inhibitors” also known as “MAOI’s”.  These drugs are often prescribed to treat people with depression.  Taking MAOI drugs can be dangerous because they significantly lower or “inhibit” your monoamine oxidase A enzyme, abbreviated MAO-A. MAO-A is a critical enzyme.  MAO-A acts like a broom, busily sweeping out tyramine, a substance found in aged food, from your body.  Without enough MAO-A, eating certain tyramine-laden foods, will cause a potentially life-threatening hypertensive crisis, a state of steeply rising heart rate and blood pressure, sweating, nausea, retching, vomiting and potential stroke.

To help you avoid catastrophe, doctors prescribing MAOI drugs provide you with a list of foods to avoid.  This list includes the obvious high tyramine culprits such as aged cheeses, sauerkraut, cured meats, beer and fermented soy products.

How does ingesting tyramine endanger someone with familial dysautonomia? Researchers discovered that in the FD body, there’s insufficient MAO-A, just as if taking an MAOI drug.  Consequently, when tyramine floods the FD body, there’s little defense.  Without enough MAO-A to flush away the onslaught of tyramine, heart rate and blood pressure rise, sweating, nausea, retching and vomiting occur.  Those with FD risk inhaling their own secretions and may require suctioning to avoid a pneumonia.  Vital signs can steeply rise and may cause a stroke.  Sometimes large doses of valium are needed to calm the autonomic system.

Beware! Tyramine can enter the system by mouth, but also through a gastrostomy tube directly inserted into the stomach.  Commercial formulas and homemade liquified foods may contain tyramine.  If an FD patient is in critical condition, total peripheral nutrition through a vein may contain tyramine. Be on guard in all settings for tyramine to enter the body.

Fortunately, FD researchers at Fordham University discovered that Pulmicort and Flovent elevate MAO-A to some extent, giving the FD body a bit more latitude to manage an increase in tyramine levels.


Ann Slaw, JD
President, FD NOW
Parent to young adult with familial dysautonomia