Types of medicine
What Is an MAOI? Why Medicine Labels Warn About It
MAOI · say it: M-A-O-IAlso written: monoamine oxidase inhibitor, MAO inhibitor, MAOIs, Monoamine Oxidase Inhibitor, MAOI
Short answer
An MAOI (monoamine oxidase inhibitor) is a type of medicine, mainly an older antidepressant, with important food and drug interaction warnings.
What it means
MAOI stands for monoamine oxidase inhibitor. These medicines block an enzyme called monoamine oxidase, which breaks down brain chemicals such as serotonin, noradrenaline and dopamine. They are mainly used as antidepressants, and some related medicines are used for Parkinson's disease.
MAOIs appear on many other medicine labels as a warning: 'Do not use if you are taking an MAOI or have stopped one recently'. This is because combining them with many medicines, such as other antidepressants, some cough and cold medicines and some pain medicines, can cause dangerous reactions like serotonin syndrome or a sudden rise in blood pressure. Some MAOIs also need you to avoid foods high in tyramine, such as aged cheeses.
The warning on over-the-counter products is for people who already take an MAOI. If you do not know whether you take one, a pharmacist can check your medicine list for you.
Where you may see it
- Over-the-counter cough, cold and allergy labels: 'Do not use if you are now taking an MAOI'
- Antidepressant labels under 'Contraindications'
- Pharmacy interaction checks
📄 How it looks on a report
Do not use if you are now taking a prescription monoamine oxidase inhibitor (MAOI), or for 2 weeks after stopping the MAOI drug.
🙅 What it does not mean
- The warning does not mean this product contains an MAOI. It means it can interact with one.
- Most antidepressants people take today are not MAOIs.
- It does not mean MAOIs are wrong for everyone; they need careful use and clear instructions.
🎯 Check yourself
Which of these is the right meaning of “MAOI”?
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “MAOI”
Plain-English explanations of each medicine, from its official FDA label.
- Amitriptyline
An antidepressant of the tricyclic type
- Bupropion Hydrochloride
an aminoketone antidepressant, a type of medicine used to treat depression
- Carbamazepine
a mood stabilizer, and an anticonvulsant (seizure) medicine, according to the label
- Citalopram
a selective serotonin reuptake inhibitor (SSRI), a type of antidepressant medicine
- Duloxetine
A serotonin and norepinephrine reuptake inhibitor (SNRI) type of antidepressant medicine
- Escitalopram
a selective serotonin reuptake inhibitor (SSRI), a type of antidepressant
- Fluoxetine
a selective serotonin reuptake inhibitor (SSRI), a type of antidepressant medicine
- Lithium Carbonate
A mood-stabilizing agent, which the label describes as a medicine used to treat bipolar I disorder
- Metoclopramide
A stomach and gut medicine. The label describes it as affecting how the stomach and intestines move. The label does not give an FDA drug class.
- Mirtazapine
An antidepressant medicine. The label describes it as having a tetracyclic chemical structure and belonging to the piperazino-azepine group of compounds.
🔗 Read more from trusted sources
- “MAOI” on MedlinePlus ↗
US National Library of Medicine
- NCI Dictionary definition ↗
US National Cancer Institute: “monoamine oxidase inhibitor”
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