What to know about MAOIs—including a comprehensive list‍

If you’re living with depression, or think you might be, you're likely eager to find relief. Fortunately, treatment works and psychiatrists can help, often by prescribing medications to help lessen your symptoms. There are a number of different antidepressants out there, which are diverse in how they work and their side effects. MAOIs (monoamine oxidase inhibitors) are one of the first ones approved by the FDA, and their history goes back decades. However, these days they are infrequently prescribed because of their severe, often life-threatening side effects. Other antidepressants, like SSRIs are potentially as effective and come with fewer effects.

If you’re wondering what MAOIs are all about, this article can answer some of your questions.

What are MAOIs and how do they work?

MAOIs, or monoamine oxidase inhibitors, work by blocking an enzyme called MAO (monoamine oxidase). Normally, MAO enzymes break down and remove neurotransmitters in your brain that influence your mood (like dopamine, and adrenaline)—but, MAOIs can help stop that from happening. (There are different types of MAO, like MAO-A and MAO-B, which affect a different set of neurotransmitters.) By preventing MAO from doing its job, this medication helps ensure there are more feel-good chemicals in your brain, helping to lessen symptoms of depression.

While MAOIs are prescribed primarily to treat treatment-resistant major depressive disorder (MDD) and anxiety disorders, they’re also infrequently used for other conditions, including eating disorders like bulimia nervosa, chronic fatigue syndrome, and gambling addiction. These uses of the medication are considered off-label, meaning the FDA hasn’t approved them for this purpose but there is research indicating their potential effectiveness.

Iproniazid, the original MAOI, was actually discovered by accident during tuberculosis research. The researchers found it had mood-elevating side effects and realized its potential for treating other conditions, like depression. This was when the term “antidepressant” was first coined by a psychiatrist. Iproniazid is no longer in use, and MAOIs generally are not preferred treatment due to the potential for serious side effects.

Do people still take MAOIs?

MAOIs were some of the very first medications approved for treating depression, and they played a crucial role in shaping the development of other antidepressants. However, as newer options like SSRIs and SNRIs came onto the scene, MAOIs started to lose favor due to their side effects that became more apparent in the long term. With monitoring, they may be an effective treatment option for some people though. The chemical structure of MAOIs makes it difficult for our bodies to metabolize enzymes that are important for natural functions, including blood pressure regulation and can result in life-threatening medical situations.

List of MAOIs

Here is a list of common examples of MAOIs that are legally prescribed in the U.S. with their generic and brand names:

• Phenelzine (Nardil)
  • FDA-approved for depression, panic disorder, and social anxiety disorder
• Selegine (Ensam)
  • FDA-approved for Major Depressive Disorder, a supplemental treatment option for Parkinson’s Disease
  • Off-label treatment for attention-deficit/hyperactivity disorder (ADHD)
• Tranylcypromine (Parnate)
  • Off-label uses for social anxiety disorder, panic disorder, and atypical depression
• Isocarboxazid (Marplan)

Other generic MAOI medications that were once used, but are no longer on the market, include:

• Mebanazine  
• Nialamide  
• Pheniprazine  
• Etryptamine  

The adverse side effects of MAOIs

As mentioned, MAOIs come with many severe side effects. The main safety issue when taking MAOIs is the potential for interactions with other medications—particularly those that affect serotonin, since this can result in serotonin syndrome, a rare but life-threatening condition.  

Additionally, interactions with other drugs can lead to severe and dangerous increases in blood pressure that can also put your health at risk. It’s important to understand these side effects before taking MAOIs, and your doctor will discuss these risk  before prescribing you this medication.  

Adverse side effects can include but are not limited to:

• Congestive heart failure
• Cerebrovascular events, including death
• Hypertensive crisis, a sudden, severe increase in blood pressure that can lead to heart attack and stroke
• Liver disease  
• Orthostatic hypertension

• Blood dyscrasias
• Serious dietary interactions (more on this next)
• Persistent hypotension
• Irregular heart rhythm

Other serious side effects:

• Vitamin B6 deficiency
• Diarrhea
• Dizziness
• Dry mouth
• Constipation
• Drowsiness
• Nausea
• Lightheadedness  
• Insomnia  
• Tremor
• Daytime sleepiness
• Weight gain  
• Muscle pain
• Sexual dysfunction
• Increased nervousness

Keep in mind that this is not a complete list of all possible side effects.  

You should also try to avoid discontinuing the drug without your doctor’s approval. Remember: your physician is there to help you, and will know the proper strategies for working with your needs and treatment goals. Stopping the medication too soon will lead to   serious withdrawal symptoms, which is why it’s important to work closely with  your healthcare team.  

Foods to avoid when taking MAOIs

MAOI medication makes it difficult to break down tyramine, an amino acid that naturally occurs in many foods. So if you’re taking MAOIs your doctor will likely instruct that you must  avoid such foods, like:  

• Aged cheese (like brie, camembert, cheddar, gruyere, Stilton, Roquefort, Swiss)  
• Aged meat, fish, and poultry (like bacon, corned beef, mortadella, pastrami, salami, and sausage
• Restaurant quality beef, which can be stored at undesirable temperatures
• Minced and ground meats
• Meat pâtés
• Processed soy products (including soy sauce, tofu, soybean condiments)
• Fermented vegetables and food products (like sauerkraut and kimchi)  
• Certain fruits, like raspberries, bananas, mandarins,  
• Certain vegetables, like eggplant, tomato, and broad beans
• Fermented dairy products (like kefir and buttermilk)
• Concentrated yeast extract (like Marmite, brewer's and baker's yeast
• Beer

Each MAOI works a little differently and how strictly you should follow this diet depends on which specific one you’re taking. For example, when you’re on tranylcypromine, isocarboxazid, and phenelzine, it’s likely your doctor will instruct you to follow this diet. But if you’re on selegiline you may not need to worry about it as much.

If you love cheese and meat, however, you don’t have to miss out. There are still foods in that category that are safe for you to eat while you’re on an MAOI.  

Foods safe to eat while on MAOIs:

• Fresh, non-matured, pasteurized cheeses (mascarpone, ricotta, mozzarella, cheddar, and goat cheese)
• Fresh, properly handled, and stored meat, poultry fish
• Fresh and properly stored vegetables and fruits
• Properly stored fresh soy products
• Fresh milk
• Nuts  

All foods that are considered ‘safe’ to have while on MAOIs must be properly stored, otherwise the risk for complications increases. The aim is to eat whole and fresh, which is not unlike many health diets which encourage whole and healthy foods. Following a healthy diet is helpful for many reasons, but minimizing adverse effects on your MAOI diet is a must.

Are MAOIs a good choice for my depression?

When it comes to treating depression, finding the right medication can be a complex process, and it takes time. Whether MAOIs are a good choice for your depression requires careful consideration and consultation with your healthcare provider.  

MAOIs aren’t considered a primary treatment choice because they have many side effects—including potentially life-threatening ones—and require a strict diet. Fortunately there are many other medications out there, which can be just as effective without the same risky side effects of MAOIs.  A mental healthcare professional like a psychiatrist can talk to you about other antidepressants and treatment options  more in-depth, and help decide which one can help.

With Talkiatry, you can see a psychiatrist from the comfort of your home, and you can schedule your first appointment in a matter of days. To get started, take our free online assessment, to get matched with a psychiatrist.  

FAQ

Here's what else to know about MAOIs.

Is Prozac an MAOI?

Prozac (fluoxetine) is not an MAOI. It is an SSRI (selective serotonin reuptake inhibitor)  that’s considered first-line treatment for depression and anxiety. You should not take Prozac if you’re on an MAOI. Studies have shown that taking fluoxetine— or almost any other antidepressant— with an MAOI results in “serotonergic syndrome” and side effects like hypomania, confusion, hypertension and tremors to name a few.  

Is sertraline an MAOI?

Sertraline, or otherwise known as Zoloft, is an SSRI—not an MAOI. Taking sertraline with an MAOI will cause similar complications to that of the Prozac-MAOI combination as listed above.  

What are common MAOIs?

MAOIs are still on the market, and FDA-approved brands that are available by prescription in the U.S. include Phenelzine (Nardil), Selegiline (Ensam), Tranylcypromine (Parnate), and Isocarboxazid (Marplan).  

What are other types of antidepressants?

Other antidepressant medications psychiatrists might prescribe instead of MAOIs include SSRIs, SNRIs, TCAs (tricyclic antidepressants), and atypical antidepressants.

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The information in this article is for education and informational purposes only and should never be substituted for medical advice, diagnoses, or treatment. If you or someone you know may be in danger, call 911 or the National Suicide and Crisis Lifeline at 988 right away.