tyramine A biologically active amine, derived from tyrosine, that mimics the effects of adrenaline, causing increased heart activity and raising blood pressure. It occurs naturally in body tissues and can also be found in ergot, mistletoe, putrefied animal tissue, and cheese. Certain antidepressant drugs, called monoamine oxidase inhibitors (MAO inhibitors), prevent the normal metabolism of tyramine, leading to dangerously high blood pressure. Hence people prescribed such drugs are advised not to eat cheese.

tyramine The amine formed by decarboxylation of the amino acid tyrosine.

tyramine (ty-ră-meen) n. an amine naturally occurring in cheese. It has a similar effect in the body to that of adrenaline. This effect can be dangerous in patients taking MAO inhibitors (antidepressants), in whom blood pressure may become very high.