Most monoamine oxidase (MAO) inhibitors are used primarily to treat severe depression but are also used to treat phobias and anxiety disorders. First-generation MAO inhibitors include isocarboxazid (Marplan), phenelzine (Nardil), and tranylcypromine (Parnate). Newer-generation MAO inhibitors with lower toxicity include selegiline (Eldepryl, Emsam, Zelapar) and rasagiline (Azilect), also used in the treatment of Parkinson disease, and moclobemide (Aurorix, Manerix), a much less toxic antidepressant that is available in many countries, but not in the United States. Multiple other MAO inhibitors are marketed outside the United States to treat depression, anxiety disorders, Parkinson disease, and bacterial infections. Serious toxicity from MAO inhibitors occurs with overdose or owing to interactions with certain other drugs or foods (Table II–37).