MAOIs (Monoamine oxidase inhibitors) refer to the group of antidepressant drugs that inhibit the enzyme monoamine oxidase (MAO) in the brain and raise the levels of certain neurotransmitters, such as norepinephrine, dopamine, and serotonin. MAOIs are potent anti-depressants thought to regulate chemicals in the central nervous system ; they should rarely be the first medication used because they may interact dangerously with many other medications, foods and beverages