Final answer:
Phenelzine, isocarboxazid, and tranylcypromine are MAOIs used to treat depression, particularly when other antidepressant treatments have not been successful. They work by increasing neurotransmitter levels, but are less commonly used due to potential risks and the need for dietary restrictions.
Step-by-step explanation:
Phenelzine, isocarboxazid, and tranylcypromine are medications used to treat depression. These drugs are classified as Monoamine Oxidase Inhibitors (MAOIs), which work by inhibiting the action of the enzyme monoamine oxidase, responsible for breaking down neurotransmitters, such as serotonin, dopamine, and norepinephrine. By preventing this breakdown, MAOIs increase the levels of these neurotransmitters in the brain, which helps to alleviate depressive symptoms.
MAOIs, like phenelzine (Nardil), isocarboxazid (Marplan), and tranylcypromine (Parnate), are considered last-line treatments for depression due to their potential toxicity and the risk of lethal food and drug interactions. They are often prescribed when other antidepressants have failed to provide relief. These medications may also be used for certain anxiety disorders and phobias that have depressive features. It is crucial for patients on MAOIs to follow specific dietary restrictions to avoid severe side effects, as these drugs can interact with certain foods and other medications.