There are a number of different MAOI antidepressants.
|Brand name||Chemical name|
Monoamine Oxidase Inhibitor Antidepressants (MAOIs) work by binding with and stopping the activity of monoamine oxidase, an enzyme found throughout the body. Monoamine oxidase breaks down a number of chemicals made and used by the body and brain. These chemicals include noradrenaline (also called norepinephrine) and serotonin as well as other chemicals made by the cells in the brain. Noradrenaline and serotonin are neurotransmitters by which the brain cells connect and communicate with each other. Monoamine oxidase inhibitor antidepressants increase the amount of these chemicals in the brain.
MAOIs also increase the amounts of other chemicals in the body and especially some chemicals which are found in food and other medications. Because they increase chemicals other than noradrenaline and serotonin MAOIs can have serious and dangerous side effects if you are not careful about certain foods and other drugs. Read very carefully the sections below on drug and food interactions.
Over many years of study and use MAOIs have been shown to improve symptoms of depression and anxiety.
Common side effects include:
Effect on weight and sleep
MAOIs can cause:
An overdose of an MAOI is dangerous. Deaths have occurred with large overdoses. An overdose causes confusion and coma. It can also cause high blood pressure and stop the heart. Go to hospital immediately.
MAOIs may increase the effect of alcohol and alcohol increases the drowsiness effect of MAOIs.
A number of medications and drugs can cause a dangerous increase in blood pressure when taken with an MAOI. These include:
MAOIs increase the effect of any drug that causes drowsiness or lowered blood pressure. (However, they can reduce the effect of some antihypertensive (blood pressure controlling) medications).
These interactions between MAOIs and other medications may mean that the dose of the other medications you are taking will need to be adjusted.
Some foods contain tyramine which can raise blood pressure with MOAIs. You should check with your doctor what these are, but examples of some foods you should avoid while taking MAOIs (because they can cause serious problems) are:
MAOIs have not been shown to be harmful to the foetus in pregnancy although there have been few studies in humans. MAOIs appear in breast milk. There have been no studies of the safety of this for babies. If the mother's treatment needs to continue the manufacturers recommends that the baby be weaned. Otherwise, the manufacturers recommend that the antidepressant be stopped if a mother is breast feeding.
MAOIs are not recommended for children.
Antidepressants are not addictive. However, some people experience withdrawal effects on stopping their antidepressant. Reactions vary between medications and between people. The effect of both Parnate and Nardil stop slowly. As a result, although withdrawal effects have been reported, they are uncommon with MAOIs.
The starting dose is usually very small and is gradually increased. This allows the dose to be increased to levels that work against depression. Some people will need higher doses.
Morning dosage is most common as most people find that MAOIs disturb sleep. The time of day the dose is taken does not change its effectiveness against depression.
If a dose is missed take it as soon as possible. If a morning dose is missed it can be taken later in the morning. Do not take it later than that but take only the ordinary morning dose next morning.
|Name||Chemical name||Common dose*||Most common time of dose|
|Parnate||Tranylcypromine||20mgm - 60mgm||Morning|
|Nardil||Phenelzine||30mgm - 90mgm||Morning|
|* with careful observation these doses may be considerably increased by your doctor|
You will need to take the antidepressant for at least 6 to 9 months after your symptoms disappear. Stopping your antidepressant too early increases your chances of suffering a recurrence of depression.
MAOIs have been in use for more than 40 years. Some people have taken them for that length of time. No extra problems have emerged beyond the common side effects mentioned above.
Last reviewed and updated: 15 January 2007