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Detailed below is information regarding what an MAOI does, how it works, warnings, MAOI side effects and alternate solutions to MAOI's.

What is an MAOI?

MAOI is an acronym for Monoamine Oxidase Inhibitor

Description:

Monoamine oxidase inhibitors are a class of antidepressants used for the treatment of depression. Due to the potential for serious dietary and drug interactions they are prescribed less frequently than other classes of antidepressant medications, such as Selective Serotonin Reuptake Inhibitors (SSRIs) or tricyclics. However, in some cases where individuals prove unresponsive to other treatments, MAOIs have been tried with marked success. They can be especially effective in treating atypical depression, and have been effective in helping smokers quit.

MAOI Treatment and usage:

MAOIs were previously prescribed for people who proved resistant to tricyclic antidepressant therapy, but newer MAOI medications are sometimes utilized as a first-line therapy. They are also used for treating social anxiety, agoraphobia, panic disorder and borderline personality disorder.

MAOI Method of action:

A depressive disorder is believed to be caused by a chemical imbalance in the brain. Monoamine neurotransmitters like serotonin, norepinephrine and dopamine are used to relay signals between nerve cells, and they regulate important functions throughout the body. Once these neurotransmitters have acted by sending a message in the brain, they are absorbed by a protein called monoamine oxidase, which is also referred to as a monoamine transporter. If too many monoamines are absorbed, a chemical imbalance occurs in the brain.

MAOIs work by inhibiting the activity of monoamine oxidase, preventing the breakdown of the brain’s monoamine neurotransmitters. This effect is thought to increase the available stores of serotonin, norepinephrine and dopamine. When these excess neurotransmitters are not broken down and absorbed, they begin to build up in the brain. Since depression may be associated with low stores of monoamine neurotransmitters, increasing them may help to alleviate depressive symptoms.

Warnings or dangers associated with MAOIs:

When taken orally, MAOIs inhibit the metabolic breakdown of dietary amines. Sufficient intestinal inhibition can lead to hypertensive crisis when foods containing tyramine are consumed or hyperserotonemia (elevated serotonin levels) if foods containing tryptophan are consumed. Tyramine is a building block of norepinephrine, and is commonly found in foods such as chocolate, alcoholic beverages, Chianti and other aged wines, fish, and fermented foods such as sauerkraut, meat and yeast extracts, soy sauce, aged cheese, soy bean condiments, and processed meat.

MAOIs inhibit monoamine oxidase and so the body cannot rid itself of excess norepinephrine. Raised levels of norepinephrine may lead to a hypertensive crisis and even cause intracerebral hemorrhage and death after the consumption of certain types of tyramine-containing foods or drinks. Hypertensive crises sometimes result in stroke or cardiac arrhythmia if left untreated.

Combined use of non-selective MAO inhibitors and serotonergic drugs (SSRIs, MDMA, or other phenylethylamines) is likely to lead to serotonin syndrome, a rare but serious and potentially life-threatening hyperserotonergic medical condition. Serotonin syndrome can also occur when combining MAOIs with certain opiods like Meperidine. MAOIs may not be combined with other antidepressants, most notably tricyclics, as this too may result in hypertensive crisis.

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MAOI Side effects:

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The most common side effect when taking an MAOI is insomnia. Other common adverse reactions include dry mouth, dizziness, feelings of lightheadedness, an excessive drop in blood pressure when standing, constipation, and weakness. Men taking MAOIs may experience sexual side effects with such symptoms as erectile dysfunction, delayed or painful ejaculation, loss of sexual sensation and anorgasmia (inability to reach orgasm). Some women have reported sexual side effects such as decreased libido and vaginal dryness.

Less common side effects reported include rash, nausea, vomiting, stiff neck, flushing, feelings of fear, chest pain, and headaches.

MAOI Overdose and withdrawal:

MAOIs are somewhat more dangerous than other antidepressant medications when consumed in excessive amounts – far more so than newer drugs such as Zoloft or Prozac. Symptoms of MAOI overdose include severe anxiety, confusion, seizures or convulsions, severe drowsiness or dizziness, cold clammy skin, rapid and irregular pulse, fever, hallucinations, severe headache, coma, tremors/spasms, excessively high or low blood pressure, muscle stiffness, difficulty breathing, extreme sleep difficulties, or abnormal irritability.

As with any type of antidepressant, sudden discontinuation of use is not advised. Your physician will likely recommend a gradual tapering off your dosage to avoid the risk of side effects. It is important to remember that once you have ceased taking the drug, you must continue to observe all dietary restrictions for at least two weeks, avoiding all the same foods and beverages as when beginning MAOI therapy.

Precautions with MAOIs in children and the elderly:

Most experts do not recommend prescribing MAOIs to children under age 16 due to the increased risk of adverse reactions associated with the drugs. Animal studies indicate MAOIs may slow growth in the young.

Older individuals are usually more sensitive to MAOIs, and may be more likely to experience dizziness or lightheadedness. Due to the danger of an abrupt increase in blood pressure (hypertensive crisis), MAO inhibitors are not usually prescribed to persons over age 60, or those with heart or blood-vessel diseases.

Types of MAOIs:

Common MAOIs include Phenelzine (Nardil), Tranylcypromine (Parnate), Isocarboxazid (Marplan), Moclobemide (Aurorix, Manerix, Moclodura), Selegiline (Selegiline, Eldepryl, Emsam), Nialamide, Iproniazid (Marsilid, Iporzid, Ipronid, Rivivol, Propilniazida), Iproclozide, and Toloxatone.

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