What are MAOIs? What do MAOIs do?
The full name for MAOIs (also called MAO inhibitors) is monoamine oxidase inhibitors, which are a type of prescription antidepressant medication used to treat panic disorder and bipolar depression. They include phenelzine (Nardil®) and tranylcypromine (Parnate®). Another drug, selegiline (Eldepryl®), which is used to treat Parkinson's disease, is also an MAOI.
Although MAOIs were a clinically proven treatment for depression, it was soon realized that there was a risk of hypertensive crisis with the concurrent ingestion of tyramine-containing foods such as aged cheeses, sour cream, beer and red wine, and processed lunch meats (bologna, salami). This finding limited their use as first line therapy, even though the need for dietary restrictions was later revisited.
However, the introduction of selective serotonin reuptake inhibitors (SSRIs) in the late 1980s would further diminish the prescribing of MAOIs to a few indications for which they are now noted. MAOIs may be used today as alternative therapy for panic disorder, social phobia, and obsessive compulsive disorder (OCD).
The recent focus on herbal products has led to the growing popularity of the herbal antidepressant Hypericum perforatum, also known as St. John's Wort. Although not officially classified as an MAOI, this herb is thought to exert part of its antidepressant effect through MAO inhibition.