Food and Drug Interactions with Monoamine Oxidase Inhibitors

Abstract

Summary The history of monoamine oxidase (MAO) inhibitors (MAOIs) is full of controversy. due to their interactions with certain foodstuffs and other drugs. The most feared interaction of MAOIs is the interaction with tyramine, a compound contained in a number of foods and beverages. This interaction may lead to hypertensive crises. the so-called ‘cheese reaction’. According to studies in healthy volunteers. selective reversible inhibitors of MAO-A (RIMAs) interact less with tyramine than nonselective irreversible MAOIs. Furthermore. the risk of interaction between tyramine and RIMAs seems to be lower than that between tyramine and irreversible MAOIs. In addition. the tyramine content of foods and beverages is lower than has previously been thought. Because no systematic clinical or naturalistic assessment of risk has been performed. the results of studies of food (and drug) interactions with MAOIs in healthy volunteers must be interpreted with caution. In patients with high individual sensitivity to the pressor effect of tyramine. or in those who consume large amounts of tyramine-containing foods and beverages. the cheese reaction may occur even with RIMAs. Dietary restriction of the type and amount of some foods and beverages may be necessary in elderly patients and in patients with cardiovascular diseases. As with the irreversible MAOIs. RIMAs may interact with over-the-counter remedies (containing dextromethorphan. phenylephrine and ephedrine). However, because of the more selective effects of RIMAs. theoretically. these interactions may be less frequent and less severe than those with other MAOIs. RIMAs may have the advantage in anaesthesia that discontinuation of these drugs 2 weeks before surgery may not be necessary. Despite the data accumulated to date, an accurate assessment of food and drug interactions with RIMAs requires more widespread use of the drugs. As such. the real risk of interactions may not be known with certainty for some time.