thoughtscape NP Psychiatry · Patient education
Isocarboxazid
Marplan
An MAOI antidepressant that needs a clear plan for food, medicines, and follow-up.
Draft for review · Clinical content has not been revalidated for this website.
Diagram: MAO-A and MAO-B inhibition is shown. A target action does not prove a separate benefit.
What it is used for
Isocarboxazid treats depression when other options have not helped enough or are unsuitable. It is not usually a first choice and is not approved for children.
Some anxiety conditions are off-label uses, not separate U.S. approvals. Ask which symptoms treatment targets and how you will judge progress.
How it works
It blocks monoamine oxidase, an enzyme that breaks down serotonin, norepinephrine, and dopamine. Changes over time may help depressive symptoms.
The enzyme effect changes how your body handles some medicines and tyramine in food. Dangerous interactions can occur even after you stop it.
What to expect over time
EARLY DAYS
Dizziness, dry mouth, or sleep changes may appear before benefit. Rise slowly and report troublesome effects.
OVER WEEKS
Mood and daily function may improve gradually. Keep follow-up; do not increase doses yourself if progress is slow.
AFTER STOPPING
Follow food restrictions for at least 2 weeks. Medicine waiting periods vary and may be longer; get a written switching plan.
Taking your medication
Take the prescribed divided doses at consistent times. Increase only on your clinician's schedule. Do not borrow another person's dosing plan.
Use the full written MAOI food list, not just examples here. Avoid alcohol and excess caffeine. Check cold, allergy, pain, and sleep products before use.
Carry an MAOI alert and tell dentists and surgical teams. Do not drive until you know the effects. Surgery or anesthesia needs an advance medication plan.
When to get help
Emergency: severe sudden headache, chest pain, pounding heart, stiff neck or sweating. Stop further doses; get emergency care. Do not treat this at home.
Emergency: fever with confusion, agitation, or stiff/twitching muscles, seizure, or collapse. Suspected overdose needs help now, even without symptoms.
Call promptly: suicidal thoughts, worsening mood, unusually high energy with little sleep, yellow skin/eyes, or dark urine. Immediate danger: 911.
Early side effects
Dizziness on standing, dry mouth, constipation, nausea, sweating, sleepiness, or insomnia can occur. Report persistent or troublesome symptoms.
Other effects to discuss
Weight or sexual changes may need review. Fainting, severe confusion, or weakness are not effects to simply tolerate; seek prompt medical advice.
What to keep track of
Keep blood-pressure, mood, and liver-test checks. Your team may check standing blood pressure and other labs based on risk. Diabetes medicines may need closer glucose monitoring. Mood and suicide-risk checks matter at every age, especially through age 24 and after dose changes. Bring your complete medicine and supplement list.
Before you start
Tell your team about heart or blood-vessel disease, high blood pressure, frequent headaches, liver, or serious kidney disease, pheochromocytoma, bipolar symptoms, seizures, diabetes, low sodium, pregnancy or breastfeeding. Several of these rule this medicine out under the U.S. label. Review every prescription, nonprescription product, and supplement before starting. Get written food and medicine-switching instructions.
Medicines & interactions
Other antidepressants & MAOIs
Never combine or cross-taper on your own. Many switches require at least 14 days; fluoxetine needs at least 5 weeks before starting isocarboxazid. Follow both product labels.
Pain, cough & stimulant products
Meperidine, tramadol, dextromethorphan, stimulants, and decongestants can be dangerous. Some waiting periods exceed 2 weeks. Ask before taking any product.
Urgent-care medicines & supplements
Tell clinicians before linezolid or IV methylene blue is considered. Buspirone, tryptophan, and St. John's wort also need specific interaction review.
Blood-pressure, allergy & sleep drugs
Some blood-pressure medicines, diuretics, antihistamines, sedatives, and anesthetics are incompatible or require a specialist plan. Do not adjust them yourself.
Tyramine-rich food and drink
Avoid aged/fermented or spoiled foods, aged cheese, cured sausage, yeast/meat extracts, soy sauce, and beer, including alcohol-free beer. The full U.S. list is broader; use your written plan.
Everyday tips
Keep the full food list handy when shopping or eating out.
Choose fresh food; store it safely and avoid questionable leftovers.
Use dose reminders and record mood, sleep, and dizziness.
Check every new medicine with a pharmacist who knows your MAOI.
Your questions, answered
What if I miss a dose?
If you are more than 2 hours late, skip it. Otherwise take it when remembered. Never double. Ask before restarting after several missed doses.
Can I stop when I feel better?
Plan a gradual taper. Abrupt stopping can cause withdrawal, sometimes confusion or hallucinations. Food precautions continue at least 2 weeks; medicine restrictions may last longer.
Is that the complete food list?
No. The U.S. label also restricts other foods and drinks. Review its full list with your team before starting and when unsure. Do not test a questionable food to see what happens.
Pregnancy or breastfeeding?
Discuss this before treatment when possible. Evidence is limited; another medicine may be preferred. Weigh treatment and untreated-illness risks rather than stopping on your own.
Storage & safety
Store tightly closed at room temperature, away from heat and moisture, locked away from children and pets. Never share; use pharmacy take-back. Suspected overdose: Poison Help 1-800-222-1222; collapse, seizure, or breathing trouble: 911. U.S. crisis support: 988.
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.