What amino acid can trigger a hypertensive crisis in patients taking MAO inhibitors?

The amino acid that can trigger a hypertensive crisis in patients taking MAO inhibitors is tyramine. MAO inhibitors are medications that block the action of monoamine oxidase, an enzyme responsible for breaking down certain neurotransmitters and other substances, including tyramine. When a patient consumes foods that are high in tyramine (such as aged cheeses, cured meats, and certain fermented products), the tyramine levels can rise significantly because the breakdown is inhibited.

In a normal physiological state, tyramine is metabolized by monoamine oxidase in the gut and liver. However, in patients taking MAO inhibitors, this metabolism is disrupted, and tyramine can enter the systemic circulation unprocessed. Elevated levels of tyramine can lead to the release of norepinephrine, resulting in excessive vasoconstriction and increased blood pressure, potentially leading to a hypertensive crisis.

Therefore, understanding the interaction between tyramine and MAO inhibitors is crucial for patient safety and dietary management when these medications are prescribed.