Final answer:
Phenelzine is an MAOI that when combined with tyramine-rich foods can lead to a hypertensive crisis due to the increased release of norepinephrine and severe rise in blood pressure. Patients on phenelzine must avoid foods like aged cheeses and cured meats to prevent this dangerous interaction.
Step-by-step explanation:
The medication phenelzine is a type of monoamine oxidase inhibitor (MAOI) used to treat depression. These drugs prevent the breakdown of neurotransmitters such as epinephrine and serotonin, which can boost mood and alleviate depressive symptoms. However, MAOIs like phenelzine can lead to dangerous interactions with tyramine-rich foods, which can result in the release of large amounts of norepinephrine, causing a hypertensive crisis. Foods high in tyramine include aged cheeses, cured meats, and fermented products. It is critical for individuals taking phenelzine to avoid these foods to minimize the risk of this severe adverse reaction.
When tyramine is ingested, it usually undergoes metabolism by monoamine oxidase. However, when this enzyme is inhibited by phenelzine, the breakdown of tyramine is blocked, which can cause large amounts of tyramine to enter the bloodstream and induce a severe increase in blood pressure. Symptoms of a hypertensive crisis may include severe headache, chest pain, palpitations, and increased intracranial pressure, which could be potentially life-threatening.The instructed avoidance of tyramine-enriched foods while prescribed phenelzine is to prevent a hypertensive crisis.
This two-line explanation sums up the mechanism behind the patient's dietary restrictions: Ingestion of tyramine-rich foods while on phenelzine could result in excessive tyramine circulation leading to a hypertensive crisis, a potentially fatal increase in blood pressure.