Monoamine Oxidase Inhibitors (MAOIs) were the among the first types of antidepressant in use. Like tricyclics, these date back to the 1950s. These medications alleviate symptoms of atypical depression, a popular form of the disease that is characterized by mood reactivity. About 40% of all depressed patients struggle with this form of depression. The atypically depressed are able to notice an improvement in mood due to positive events. MAOS work because they prohibit the activity of monoamine oxidase so it can not metabolize the neurotransmitters norepinephrine, serotonin and dopamine. This, in turn, elevates mood.
Examples of Monoamine Oxidase Inhibitor include isocarboxazid (Marplan), phenelzine (Nardil), and tranlcypromine (Parnate). MAOIs were once the most popular form of antidepressant. However, they have fallen out of favor in no small part due to their often unpleasant side effects.
- low blood pressure
- dry mouth
- decreased sexual function
- increased appetite
- increased sweating
- and trembling.
MAOI can often interact negatively with certain over the counter medicines (usually decongestants for cold and flu), and certain foods that contain substances such as tyramine. Tyramine is in many foods including chocolate and certain types of meat, cheese, wine, and pickles. Tyramine and MAOIs react together to increase blood pressure sharply. This can lead to a stroke.
If your doctor prescribes an MAOI for you, he or she should provide you with a complete list of foods and beverages to avoid at all times.
A rare and potentially life-threatening side effect of MAOIs is referred to as serotonin syndrome. This can occur when an MAOI interacts with another type of antidepressant, specifically a selective serotonin reuptake inhibitor (SSRI) such as Prozac, Celexa or Lexapro. Characterized by dangerously high levels of serotonin in the brain, the condition will present within several hours of taking a new drug or after increasing the dosage of a previously used drug.
Symptoms include: extreme agitation or restlessness, confusion, hallucinations, loss of coordination, fever, rapid changes in blood pressure, heavy sweating, overactive reflexes, nausea, vomiting and diarrhea, seizures and coma.