Abstract

We have previously drawn attention to the hypertensive attacks provoked by food substances in patients taking monoamine oxidase inhibitors for the treatment of depression or hypertension (Drug & Therap. Bull. 1963, 1, 44; 1964, 2, 28). Experimental work on patients in America¹ has confirmed that tyramine is potentiated up to a hundredfold when given orally or parenterally after a period of amine oxidase inhibition. Analysis of various cheeses^{1, 2} revealed that cheddar contained more tyramine than well matured varieties such as Camembert and was capable of producing hypertensive crisis in amounts as small as 20 G, thus confirming the earlier clinical reports.³ ECG changes have been reported during attacks and so have large rises in blood pressure of up to 120 mm Hg which may be entirely asymptomatic.^{4, 7}