Antidepressants are, today, a routine part of the treatment of depression — but they weren't always available. Monoamine oxidase inhibitors (MAOIs) were the "first kid on the block", and their potential in treating depression was discovered quite accidentally when doctors noticed that tuberculosis patients enjoyed mood improvements while on these drugs.
1. MOAIs require a strict diet
Monoamine oxidase inhibitors, which include phenelzine (Nardil), tranylcypromine (Parnate), and isocarboxazid (Marplan) as well as Selegeline and Moclobemide, lead to rising levels of a substance cause tyramine. This, in turn, means that ingesting more of this substance has the potential to lead to seriously dangerous blood pressure levels. The fact that tyramine is found in some foods as well as naturally being present in the body explains why it's well known that being on MAOIs requires a strict diet.
Patients are traditionally told to avoid a whole laundry list of foods, and these include:
- Mature cheeses
- Certain meats — such as liver, salami, pepperoni, pate, and mortadella
- Yeast extracts, such as marmite
- Soy products
- Protein extracts
- Beer and wine
- Banana peels
- The list goes on
2. MAOIs can interact with other drugs in some very dangerous ways
Taking MAOIs together with some other medications, including over-the-counter drugs and other antidepressants, can lead to very serious drug interactions. In some cases, you'll be at risk of very high blood pressure, while combining MAOIs with other drugs can lead to serotonin syndrome — which can even be deadly.
However, some drugs to avoid while you're on a monoamine oxidase inhibitor include:
- Other antidepressants — SSRIs, SNRIs, and tricyclic antidepressants.
- Medications containing pseudoephedrine, typically marketed as treatments for influenza and common colds.
- Some antihistamines.
- Some medications for asthma.
- Some antihypertensives.
- Some anesthetic agents.
3. MAOIs can lead to unpleasant side effects
The "early" side effects of monoamine oxidase inhibitors look rather a lot like those associated with many other kinds of antidepressants. They include:
- Orthostatic hypotension — low blood pressure on changing positions
- Dry mouth
In addition, MOAIs are not suitable for everyone. Children and adolescents shouldn't take them, for instance.
Why monoamine oxidase inhibitors may still be the best antidepressant for you
Your doctor may decide to prescribe you a monoamine oxidase inhibitor if you have been diagnosed with depression but other kinds of antidepressants have not proven to be effective for you. Medications belonging to this class may also benefit those with frequently recurring bouts of depression, research suggests, along with people suffering from atypical depression. If your depression features panic attacks, fear of rejection, anxiety, a higher appetite, hypersomnia (a lot of sleeping), or an increased libido, there are studies that indicate that MAOIs may serve you better than other kinds of antidepressants.
On the whole, monoamine oxidase inhibitors are no longer considered a first-line treatment for depression — over 10 percent of clinicians will never prescribe them, while nearly a third won't have recommended them to anyone over the last couple of years. They remain, however, an important tool in the antidepressant toolbox. If your doctor prescribes you a MAOI despite the fact that they are unpopular now, they will have a good reason for doing so. As a patient, you should feel free to ask what that reason is and if there are any viable alternatives. You should also make sure you understand the risks and benefits — and know how to use your monoamine oxidase inhibitor safely — before you begin taking it.