Monoamine oxidase inhibitors (MAOIs) are agents that inhibit the enzyme monoamine oxidase (MAO), which comprises two distinct subtypes, MAOA and MAOB.
MAO degrades the monoamine neurotransmitters adrenaline, dopamine, melatonin, noradrenaline, phenethylamine, serotonin and tyramine. MAOA selectively degrades adrenaline, noradrenaline, melatonin and serotonin, whereas MAOB selectively degrades phenethylamine. Both subtypes degrade dopamine and tyramine. MAOB is selectively expressed in brain areas where dopamine is present.
Reversibility and selectivityEdit
MAOIs possess two properties that dictate their side effects and therapeutic use: selectivity (i.e., which subtype they prefer to inhibit over the other) and reversibility. The older agents are neither selective nor reversible. These agents are denoted by iMAOIs. This means that patients taking them must avoid tyramine-laced foods due to the potential for hypertensive crises to result. Whereas the newer agents usually possess either selectivity or reversibility, or both. These agents usually do not require the dietary restrictions that their irreversible and non-selective counterparts. MAOB-selective irreversible inhibitors are used to treat Parkinson's disease whereas MAOA selective and reversible inhibitors (so called reversible inhibitors of monoamine oxidase A [RIMAs]) are used to treat depression and anxiety disorders.
List of available agentsEdit
- Iproniazid (brand name: Marsilid)
- Isocarboxazid (brand name: Marplan)
- Phenelzine (brand name: Nardil)
- Tranylcypromine (brand name: Parnate)
MAO-B selective irreversible inhibitorsEdit
- Rasagiline (brand name: Azilect)
- Selegiline (brand names: Atapyrl, Eldepryl, Emsam, Selgene, Zelapar)
Reversible inhibitors of monoamine oxidase AEdit
- Brofaromine (brand name: Consonar)
- Moclobemide (brand names: Aurorix, Manerix)
- Pirlindole (brand names: Implementor, Normazidol (Нормазидол), Pyrazidol (Пиразидол))
- NCBI Bookshelf provides free book resources on this topic.
- PubMed provides review articles from the past five years (limit to free review articles or to systematic reviews)
- The TRIP database provides clinical publications about evidence-based medicine.