Marplan (generic: isocarboxazid) is a prescription medication used to treat depression. Because of its potentially serious side effects, it is often used only after other antidepressants haven't worked. Marplan belongs to a group of drugs called monoamine oxidase (MAO) inhibitors. It works by increasing the levels of certain natural chemicals in the brain that affect your mood and help maintain mental balance.

Marplan comes in tablet form. It is usually taken 2 to 4 times daily, with or without food.

Common side effects of Marplan include nausea, dry mouth, and dizziness. Marplan can cause drowsiness. Do not drive or operate heavy machinery until you know how it affects you.