Monoamine oxidase inhibitors, known as MAO inhibitors or MAOIs, are drugs used to treat depression and anxiety. These drugs can be quite dangerous and are usually employed when other lines of treatment are not effective for a patient. They are available by prescription only and patients on MAO inhibitors must observe a number of precautions. Two examples of such drugs on the market are phenelzine and selegeline.
These drugs work by interfering with the action of monoamine oxidase. This enzyme is used by the body to break down monoamines. These include a large group of neurotransmitters as well as amines in food. People with depression can have low levels of monoamine neurotransmitters like serotonin, epinephrine, melatonin, and norepinephrine. These contribute to a chemical imbalance that leads to depression. By blocking the enzyme that acts to break down these neurotransmitters, an MAO inhibitor allows levels of these transmitters to rise in the brain, contributing to a more balanced mood on the part of the patient.
While depression is the primary condition treated with MAO inhibitors, patients with some forms of anxiety, as well as Parkinson's disease, can also benefit from such drugs. The danger of MAO inhibitors lies in what makes them so effective; because the body cannot metabolize amines and monoamines properly while these drugs are in use, their levels in the body can build up, putting the patient in danger. Mixing MAOIs with medication that contain epinephrine, for example, will cause levels of this neurotransmitter to rise, leading to a dangerous spike in blood pressure.
There is a long list of medications that are dangerous with MAO inhibitors and such medications have warning labels to alert patients to the fact that they can interact badly with MAOIs. In addition, there are dietary conflicts that can be present as well. Foods that contain tryptophan or tyramine, present in aged and fermented foods, can interact poorly with an MAO inhibitor. Patients who consume these foods can die from the drug interaction.
When an MAO inhibitor is recommended for a patient, the patient should ask why the drug is being prescribed, how to take the drug, and what kind of precautions need to be taken. Many doctors provide their patients with a printout of potentially dangerous foods and medications to avoid. Patients should make sure that there is a note on their charts and at the pharmacy alerting people to the fact that they are taking an MAOI.