thoughtscape NP Psychiatry · Patient education
Phenelzine
Nardil
An MAOI for depression after other treatments. Food, medicine, and blood-pressure precautions are essential.
Draft for review · Clinical content has not been revalidated for this website.
Food and medicine precautions begin before treatment and continue for at least 14 days after the last dose
What it is used for
Treats depression, often when other antidepressants have not helped. It can be considered for depression with atypical features.
Social anxiety and panic disorder are off-label uses. Discuss your treatment goal; no medicine guarantees relief or works for everyone.
How it works
Blocks enzymes called MAO-A and MAO-B, reducing breakdown of serotonin, norepinephrine, and dopamine. The full mechanism is not settled.
MAO also handles tyramine in food. Enzyme effects persist after the drug leaves the blood, so interaction precautions continue after stopping.
What to expect over time
BEFORE THE FIRST DOSE
Finish the agreed washout from other medicines. Get a written food list, interaction check, and emergency plan first.
DURING DOSE CHANGES
Watch standing dizziness and blood pressure. Dose increases depend on tolerability, not a requirement to push through side effects.
OVER SEVERAL WEEKS
Benefit can take weeks at a suitable dose. Keep follow-ups; the prescriber weighs symptom change against adverse effects.
Taking your medication
Take the exact divided doses prescribed. Do not change timing or put all doses at bedtime yourself; rise slowly from sitting or lying.
Check all new medicines, cold remedies, supplements, and substances. Avoid alcohol. Do not drive until you know how treatment affects you.
Do not stop abruptly or double doses. Follow food and drug precautions for at least two weeks after stopping, longer if instructed.
When to get help
Sudden severe headache, stiff neck, chest pain, or pounding heart: hold further doses and call 911. Do not wait for a home BP reading.
Fever with confusion or stiff/twitching muscles, seizure, collapse, or breathing trouble needs emergency care. Do not take more doses.
Report suicidal thoughts, major mood change, faintness, or jaundice promptly. Immediate danger or severe symptoms require emergency care.
Early side effects
Standing dizziness, drowsiness, or insomnia, fatigue, dry mouth, and constipation can occur. Report troublesome symptoms before dose increases.
Other effects to discuss
Weight gain, swelling, and sexual difficulties can occur. Report tingling or numbness; do not assume B6 deficiency or take high doses yourself.
What to keep track of
Check seated and standing blood pressure, weight, mood, sleep, falls and new medicines. Liver/kidney assessment helps identify reasons not to start; liver tests may also be needed during treatment. Diabetes medicines may need review. Food precautions do not prevent every serious adverse effect.
Before you start
Discuss heart failure, kidney or liver disease, abnormal liver tests, pheochromocytoma, seizures, bipolar symptoms, and self-harm risk. Review all medicines, allergies, and completed washouts. Carry MAOI identification and tell every clinician, dentist, and pharmacist, including before surgery or anesthesia.
Medicines & interactions
Antidepressants / other MAOIs
Do not combine or cross-taper on your own. Buspirone and bupropion are also contraindicated. The washout depends on both medicines; see below.
Cold, cough, and pain products
Avoid dextromethorphan, pseudoephedrine, and phenylephrine. Meperidine and tramadol are dangerous combinations. Have every cold or pain product checked.
Stimulants / supplements
Do not combine with amphetamines, methylphenidate, cocaine, or MDMA. Check triptans, St. John's wort, tryptophan, tyrosine, and other supplements.
Blood-pressure / diabetes medicines
Blood-pressure drugs may worsen faintness; guanethidine is contraindicated. Insulin or other diabetes treatment may need adjustment. Do not self-adjust.
Procedures / urgent treatment
Anesthesia, dental injections, linezolid, and IV methylene blue need specialist planning. Tell the team even if phenelzine was recently stopped.
Everyday tips
Avoid aged cheeses, cured, or fermented meats, pickled fish, concentrated yeast/meat extracts, fermented soy, sauerkraut, and spoiled or poorly stored protein foods.
The U.S. label also restricts liver, fava-bean pods, and yogurt. Cream cheese and cottage cheese are exceptions on its cheese list; ask before substitutions.
Avoid alcohol, beer, and wine, including alcohol-free or reduced-alcohol versions. Avoid excess caffeine and chocolate; agree on specific limits with your team.
Get a complete written MAOI food guide before starting. This summary is not the whole diet plan. Do not assume all fresh foods or bottled drinks are safe.
Your questions, answered
What if I miss a dose?
Take it when remembered unless the next dose is near; then skip it. Never double. Ask if you have missed several doses.
How long are switching gaps?
Usually at least 14 days; before phenelzine, at least 5 weeks after fluoxetine and 21 days after vortioxetine. Some situations require longer. Get written dates.
Can I stop when I feel better?
Arrange a gradual taper, often over weeks. Abrupt stopping can cause withdrawal or relapse. Food and medicine precautions continue after the final dose.
Pregnancy or breastfeeding?
Evidence is limited. Discuss better-studied options and the risks of untreated illness with your prescriber; do not stop abruptly on your own.
Storage & safety
Store securely in the original container; never share. Suspected overdose needs immediate hospital assessment even if initially well; call U.S. Poison Help 1-800-222-1222. Call 911 for collapse, seizure, breathing difficulty, inability to wake, or imminent self-harm. Do not try home blood-pressure rescue.
About this information
For general information only; not a substitute for individualized medical advice. This sheet does not cover every risk or interaction. Ask your prescriber or pharmacist before changing how you take this medication.
Sources
Educational inclusion does not mean this medication or its indications are treated at this practice. Review the guide for your exact product with your prescriber or pharmacist.