MAOI's cheese reaction

Question 1

Tyramine is a monoamine (derived from tyrosine, an amino acid) which is found in various foods, and is an indirect sympathomimetic that can cause a hypertensive reaction in patients receiving MAOI therapy.

Note: ‘indirect sympathomimetic refers to the fact that it displaces norepinephrine from neurones.

Monoamine oxidase is found in the gastrointestinal tract and inactivates tyramine; when drugs prevent the catabolism of exogenous tyramine, this monoamine is absorbed and displaces norepinephrine from sympathetic nerve ending and epinephrine from the adrenal glands. If a sufficient amount of pressor (a pressor is a substance that increases blood pressure by stimulating constriction of the blood vessels) amines are released, a patient may experience a severe occipital or temporal headache, diaphoresis, mydriasis, nuchal rigidity (neck stiffness), palpitations, and the elevation of both diastolic and systolic blood pressure may ensue.

For this reason, the following dietary restrictions are required for patients receiving MAOIs:-

Answer 1

Alcoholic beverages (particularly Chianti wine and vermouth)
Banana peels
Bean curd
Broad (fava) bean pods
Cheese (but cream cheese and cottage cheese have no detectable level of tyramine, so are allowed)
Sauerkraut
Unfresh meat and liver
Yeasts and extracts (e.g. Marmite)