Is Prozac An MAOI?

Prozac is an SSRI—and it can never be taken with an MAOI

Prozac pills
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Prozac, or fluoxetine, is not a monoamine oxidase inhibitor (MAOI) but rather a selective serotonin reuptake inhibitor antidepressant. Prozac should never be taken with an MAOI. 

MAOIs were the first type of antidepressants developed. Because of the way they work, MAOIs have significant dietary restrictions and important limitations on what other drugs may be taken at the same time. For this reason, they are not considered to be the drugs of first choice when treating depression.

MAOIs have been found to be of most use in treating atypical depression, which is characterized by overeating, sleeping too much, sensitivity to rejection, leaden paralysis (heavy, leaden feelings in arms or legs) and strong reactions to your environment.

How Do MAOIs Work?

The brain's neurotransmittersserotonin, norepinephrine, and dopamine—are all monoamines, meaning they have a single amino acid group. In the gap between nerve cells, the synapse, used neurotransmitters are destroyed by an enzyme called monoamine oxidase (MAO). If this results in concentrations of neurotransmitters that are too low, depression can result. MAOIs work by blocking the activity of this enzyme, resulting in higher levels of neurotransmitters in the brain, which relieves depression.

Which Drugs Are MAOIs?

MAOI antidepressants include:

  • Marplan - generic isocarboxazid
  • Nardil - phenelzine
  • Parnate - tranylcypromine
  • Manerix - moclobemide (available outside the United States)
  • Emsam - selegiline transdermal

Why Do MAOIs Have Dietary Restrictions?

The enzyme monoamine oxidase (MAO) has another role in the brain: it controls levels of tyramine, which affects blood pressure. When an MAOI blocks the activity of the MAO enzyme, it can raise the levels of tyramine in your body, which can cause blood pressure to go up.

A high spike in tyramine can lead to a sudden jump in blood pressure, called a hypertensive crisis, which can lead to stroke and death. To help prevent this, foods high in tyramine are off-limits to people taking MAOIs. For more, see MAOIs and Diet.

What Are The MAOI Drug Interactions?

Many drugs, including prescription medications, over-the-counter drugs, and street drugs, should be avoided when taking an MAOI antidepressant. The most common of these include:

*Starred items are highly dangerous when combined with MAOIs.

The general rule of thumb when switching from an MAOI to another antidepressant is to wait two weeks between stopping one and starting the other. However, because Prozac is slow to leave the body, at least five weeks should be allowed between stopping Prozac and starting an MAOI to avoid possibly lethal complications.

It is vital that you tell your doctor about all drugs of all kinds you are taking or take as needed when you discuss starting an MAOI.

To be safe when taking an MAOI, do not take any prescription or over-the-counter medication without first checking with your doctor.

Other Precautions and Warnings for MAOIs

  • Safety has not been established for MAOIs during pregnancy and while breastfeeding; thus, use is not recommended.
  • Elderly patients are more likely to experience dizziness or lightheadedness while taking one of these medications.
  • Insulin dosage may need to be adjusted when taking an MAOI.
  • Persons taking Nardil should not use the artificial sweetener aspartame.
  • Unless you are experiencing severe side effects, do not stop taking an MAOI abruptly. Work with your doctor to taper off the medication gradually.

    Stop taking your MAOI and get emergency help immediately if you experience any of the following symptoms of a hypertensive crisis:

    • Severe chest pain; severe headache; stiff or sore neck; enlarged pupils; fast or slow heartbeat; increased sensitivity of eyes to light; increased sweating (possibly with fever or cold, clammy skin); nausea and vomiting.

    Disclaimer: This is not intended to be all-inclusive or to replace information provided by your doctor or with prescriptions from drug manufacturers.


    Mayo Foundation for Medical Education and Research.

    Depression and Bipolar Support Alliance. Monoamine Oxidase Inhibitors. 

    NIH, Medline Plus. 

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