Phenelzine Health Article

Definition

Phenelzine is classified as a monoamine oxidase (MAO) inhibitor. In the United States, phenelzine is sold under the brand name Nardil.

Purpose

Phenelzine is used to treat certain types of serious depression and severe depression complicated by severe anxiety that do not respond to other antidepressant drugs.

Description

Phenelzine is a member of a class of drugs called monoamine oxidase inhibitors. Monoamine oxidase, or MAO, is an enzyme found throughout the body. In the brain, MAO breaks down norepinephrine and serotonin, two naturally occurring chemicals that are important in maintaining mental well-being and preventing depression. Monoamine oxidase inhibitors, such as phenelzine, reduce the activity of MAO. Less norepinephrine and serotonin are broken down, so their levels rise. This helps to lift depression.

Phenelzine is effective for treating depression, especially complicated types of depression that have not responded to more traditional antidepressants. However, phenelzine also affects the MAO enzyme in many other areas of the body. This accounts for the large number of serious side effects and drug interactions it causes.

Recommended dosage

Adults are usually started on 15 mg of phenelzine three times per day. This dosage can be increased to a maximum of 90 mg per day if lower doses are not effective, and the patient can tolerate the higher dose without excessive side effects. After the maximum benefits are achieved, the dosage is usually lowered over several weeks to the lowest level that is effective. This could be as little as 15 mg daily or every other day.

In general, phenelzine is not recommended for people over the age of 60. When it is used by the elderly, the starting dosage is usually 15 mg taken in the morning. This dose may be gradually increased over time to a maximum of 60 mg. Phenelzine is not frequently given to children under the age of 16, and recommended dosage in such cases has not been established.

Phenelzine can be taken with food or on an empty stomach. It should not be taken close to bedtime, because it can interfere with sleep. The benefits of this drug may not become apparent for as long as four to eight weeks. Patients should be aware of this and continue taking the drug as directed even if they do not see an immediate improvement.