Why Does Phenelzine Require Dietary Restrictions?
Phenelzine, a monoamine oxidase inhibitor (MAOI) antidepressant, blocks the enzyme that breaks down tyramine in food. Eating high-tyramine foods causes tyramine buildup, triggering a hypertensive crisis—sudden, dangerous spikes in blood pressure that can lead to stroke or heart attack.[1]
Foods to Strictly Avoid
Skip these high-tyramine items entirely while on phenelzine:
- Aged cheeses (cheddar, blue, Camembert, Parmesan; fresh cheeses like cottage or ricotta are usually safe).
- Cured, smoked, or aged meats (salami, pepperoni, sausage, bacon, liver).
- Fermented or pickled foods (sauerkraut, kimchi, pickled herring).
- Soy products (soy sauce, miso, tofu, tamari).
- Yeast extracts or spreads (Marmite, Vegemite).
- Broad beans (fava beans).
- Draft beer or red wine (some alcohols like Chianti); stick to clear spirits or non-alcoholic options.[1][2]
Foods to Limit or Eat Fresh
- Fresh meats, poultry, and fish (avoid leftovers older than 48 hours).
- Avocados, bananas, raspberries (small amounts okay if fresh).
- Chocolate, caffeine, yeast-leavened breads (moderate intake).[1]
How Long Do Restrictions Last?
Follow the diet during treatment and for 10-14 days after stopping phenelzine, as the drug lingers in the body.[2]
What Happens If You Break the Rules?
Symptoms of tyramine reaction start within 30 minutes to 2 hours: severe headache, stiff neck, fast heartbeat, chest pain, nausea, sweating. Seek emergency care immediately—it's a medical emergency.[1][2]
Tips for Patients Starting Phenelzine
Get a tyramine-restricted diet list from your doctor or pharmacist. Fresh, unprocessed foods are safest. Inform restaurants about your MAOI status. Some switch to newer antidepressants like SSRIs to skip these rules.[1]
Are There Exceptions or Drug Interactions?
Certain meds (e.g., decongestants, stimulants, other antidepressants) mimic tyramine effects—check with your doctor. Over-the-counter meds like pseudoephedrine are off-limits.[2]
[1]: FDA Label for Nardil (phenelzine)
[2]: Mayo Clinic - MAOIs and Diet