What are monoamine oxidase inhibitors MOAIs were the first class of antidepressants to be developed. They fell out of favor because of concerns about interactions with certain foods and numerous drug interactions. MOAIs elevate the levels of norepinephrine, serotonin, and dopamine by inhibiting an enzyme called monoamine oxidase. Monoamine oxidase breaks down norepinephrine, serotonin, and dopamine. When monoamine oxidase is inhibited, norepinephrine, serotonin, and dopamine are not broken down, increasing the concentration of all three neurotransmitters in the brain. They are also used for treating Parkinson's. Examples of oral MOAIs include: rasagiline (Azilect), selegiline (Eldepryl, Zelapar), isocarboxazid (Marplan), phenelzine (Nardil), and tranylcypromine (Parnate). The most common side effects of MAOIs include: Dry mouth Nausea, diarrhea or constipation Headache Drowsiness Insomnia Skin reaction at the patch site Dizziness or lightheadedness Other possible side effects include: Involuntary muscle jerks Low blood pressure Reduced sexual desire or difficulty reaching orgasm Sleep disturbances Weight gain Difficulty starting a urine flow Muscle aches Prickling or tingling sensation in the skin (paresthesia) Stopping MOAIs Stopping treatment with MAOIs has been associated with flu-like symptoms, including nausea, vomiting and feeling generally unwell (malaise). If you stop an MAOI suddenly, you're more likely to experience a withdrawal-type reaction. Rarely, discontinuation syndrome can occur, which causes uncommon withdrawal symptoms such as insomnia, confusion, detachment from reality (psychosis), agitation and convulsions. You may need to wait two or more weeks between the use of MAOIs and other antidepressants to avoid serotonin syndrome. Work with your doctor to gradually and safely decrease your dose.
