Developed in the 1960s, monoamine oxidase inhibitors are among the oldest class of antidepressants. They are generally used when other types of antidepressants have proved ineffective. They react with certain kinds of food and other medication, producing harmful side effects. Therefore, they need to be prescribed with dietary restrictions. Depression is said to be caused by chemical imbalances in the brain. Generally, depression is associated with lower levels of monoamine neurotransmitters, such as serotonin, norepinephrine, and dopamine. Once these neurotransmitters have done their job, they are acted upon by an enzyme called monoamine oxidase (MAO). Monoamine oxidase removes these neurotransmitters from the brain by metabolizing them into their metabolites. MAOIs work by blocking this clean up activity and hence allowing these monoamines to build up within the brain. As depression is caused by low levels of these neurotransmitters, allowing them to build up eases the signs and symptoms of depression. The problem is that monoamine oxidase is also responsible for the breakdown of tyramine, which is a naturally occurring amino acid that helps regulate blood pressure. Too much tyramine increases the risk of high blood pressure, stroke, and cardiac arrhythmia. It is found in various foods and a low tyramine diet is necessary for anyone taking MAOIs. Dietary Restrictions

• aged foods
• alcoholic beverages (especially chianti, sherry, liqueurs, and beer)
• alcohol-free or reduced-alcohol beer or wine
• anchovies
• bologna, pepperoni, salami, summer sausage, or any fermented sausage
• caviar
• cheeses (especially strong or aged varieties), except for cottage and cream cheese
• chicken livers
• fermented foods
• figs (canned)
• fruit: raisins, bananas (or any overripe fruit)
• meat prepared with tenderizers; unfresh meat; meat extracts; smoked or pickled meat, poultry, or fish
• soy sauce

Foods you can Eat in Moderation

• avocados
• beer
• caffeine (including chocolate, coffee, tea, cola)
• chocolate
• raspberries
• sauerkraut
• soup (canned or powdered)
• sour cream
• yogurt

In the 1960s, when the MAOIs were introduced, there were a number of deaths that occurred due to brain hemorrhage. Some patients also reported severe headaches due to increase in blood pressure. At that time the MAOIs were taken off the American market as they also seemed to cause damage to the liver, brain, and cardiovascular system. They were reintroduced into the country because some patients suffering from depression were not responding to any other form of medication. General Side Effects of Monoamine Oxidase Inhibitors Stop Medication and Seek Medical Advice if

• unusually high blood pressure
• severe chest pain
• severe headache
• increased sweating
• stiff or sore neck
• fast or slow heartbeat
• increased sensitivity to light
• nausea and vomiting

Check with Physician if You Observe

• severe dizziness or light-headedness, especially when arising from a sitting or sleeping position
• diarrhea
• pounding heart
• swelling of feet and/or lower legs
• unusual excitement or nervousness
• dark urine
• fever
• skin rash
• slurred speech
• sore throat
• staggering walk
• yellow eyes and/or skin

Mild Side Effects

• blurry vision
• decreased sexual ability
• urinary problems
• drowsiness
• mild headache
• weight gain
• increased sweating
• restlessness
• shakiness or trembling
• fatigue and weakness
• sleeping problems
• chills
• constipation
• decreased appetite
• dry mouth
• muscle twitching during sleep
• increased appetite and mild dizziness or light-headedness

Due to side effects, they are used as a last resort in treating depression and usually for atypical depressions. More Side Effects of Monoamine Oxidase Inhibitors

• Drowsiness
• Constipation
• Nausea
• Diarrhea
• Stomach upset
• Fatigue
• Dry mouth
• Dizziness
• Low blood pressure
• Lightheadedness, especially when getting up from a lying or sitting position
• Decreased urine output
• Decreased sexual function
• Sleep disturbances
• Muscle twitching
• Weight gain
• Blurred vision
• Headache
• Increased appetite
• Restlessness
• Shakiness
• Trembling
• Weakness
• Increased sweating

As we can see, there are many side effects as well as dietary restrictions when it comes to taking MAOIs. These drugs can also be dangerous when taken with other drugs including prescription drugs and some over the counter medications.