Tyramine Tessa — MAOIs & the Tyramine Hypertensive Crisis
Phenelzine finally lifts her depression — until aged cheese and tap beer send her blood pressure through the roof
Tessa's depression has finally responded to phenelzine. At a wine-and-cheese party she develops a pounding occipital headache, a stiff neck and a racing heart — her blood pressure is 210/118.
Tessa takes phenelzine, a monoamine oxidase inhibitor, for depression that has resisted other treatments. MAOIs work by blocking the enzyme that breaks down norepinephrine, serotonin and dopamine — but that same enzyme, MAO-A in the gut, is also what detoxifies tyramine in food. On an MAOI, tyramine from aged cheeses, cured meats, tap beer, sauerkraut and soy sauce floods into the bloodstream, releases massive norepinephrine, and triggers a hypertensive crisis: occipital headache, stiff neck, palpitations, flushing and a blood pressure that can stroke. The teaching list is long because the enzyme stays inhibited for weeks after the last dose.
Read Tyramine Tessa's full story →The story arc
The setup
After two failed antidepressants, Tessa starts phenelzine and receives the MAOI diet teaching sheet: no aged cheeses, cured meats, tap beer, fermented foods or soy sauce.
The turn
At a party, Tessa eats aged cheddar and salami, reasoning that a small amount cannot hurt.
The crisis
Within an hour she has a severe occipital headache, neck stiffness, palpitations, sweating and a blood pressure of 210/118.
The save
Tessa is treated with IV phentolamine to lower her blood pressure, and she relearns the diet — including the rule that restrictions continue for two weeks after stopping the MAOI.
NCLEX study section — MAOIs & the Tyramine Hypertensive Crisis
What this chapter is testing: the recognition cues, the numbers and the priority action.
Study section: Pharmacology
Take this chapter into practice questions on the same topic.