First described in a Bristish pharmacist’s wife a very long time ago… poor woman, every time she ate cheese she developed a severe headache.  Gradually discovered to be an interaction between monoamine oxidase inhibitors (MAOIs) and tyramine-containing foods.

Here’s why:

- Tyramine = a monoamine. This substance indirectly increases release of catecholamines.

- The enzyme monoamine oxidase naturally breaks down tyramine and other monoamine chemicals.

- MAOIs blocks this breakdown pathway, increasing levels of tyramine and thereby increasing catecholamines such as norepinephrine. 

MAOI + Excess tyramine = potential for tyramine reaction

**Also beware of serotonin syndrome in patients on MAOIs, but that’s a separate story

MAOIs:

Antidepressants – not used commonly anymore – phenylzine, selegiline, isocarboxazid

Occasionally used to treat Alzheimer’s Dementia, Parkinson’s Disease

*Linezolid – antibiotic with some MAOI properties

Foods high in tyramine: 

Aged cheese

Cured meats

Smoked fish

Certain alcohols - some beer, red wine

Other fermented foods

(Of course others as well… a quick google search will help in a patient you are concerned about)

Signs/Sx –  Symptoms of adrenergic excess

- hypertension, diaphoresis, mydriasis

- headaches, CVA, palpitations, arrythmias

Treatment – 

- Treat hypertensive emergency, lower blood pressure

- Avoid triggers

References:

Sathyanarayana Rao, T S, and Vikram K Yeragani. “Hypertensive crisis and cheese.” Indian journal of psychiatry vol. 51,1 (2009): 65-6. doi:10.4103/0019-5545.44910

Goldberg LI. Monoamine Oxidase Inhibitors: Adverse Reactions and Possible Mechanisms. JAMA. 1964;190(5):456–462. doi:10.1001/jama.1964.03070180054008