MAO-B (Monoamine Oxidase-B) Inhibitors

MAO-B inhibitors are molecules that modify the metabolic pathways that lead to the breakdown of dopamine, a neurotransmitter, or chemical messenger, required to relay electric signals between two nerve cells and between the brain and muscles.

In Parkinson’s disease, the dopamine-producing nerve cells progressively deteriorate in specific parts of the brain, leading to a range of symptoms.

How MAO-B inhibitors work

Although restoring dopamine levels cannot cure Parkinson’s disease, it can alleviate many of the symptoms brought about because of a decrease in this neurotransmitter.

Monoamine oxidase-B (MAO-B) is an enzyme responsible for the chemical breakdown of dopamine in the brain. MAO-B inhibitors act by inhibiting the activity of this enzyme and therefore slowing the breakdown of dopamine.

MAO-B inhibitors can be given either as a monotherapy or they can be combined with carbidopa-levodopa therapy.

Although MAO-B inhibitors have been shown to bring about only a modest decrease in the severity of Parkinson’s symptoms, the use of these medications can delay the reliance on levodopa.

Examples of MAO-B inhibitors used in Parkinson’s disease


Selegiline is one of the most commonly used MAO-B inhibitors and is the active ingredient in medications such as Eldepryl, Carbex and Zelapar 


Rasagiline is as an irreversible MAO-B inhibitor and the active agent of Azilect. It is frequently prescribed to manage symptoms of Parkinson’s disease.


Safinamide is the active agent of Xadago. Although it has other modes of action, it also acts as an MAO-B inhibitor. In many cases, the effects of levodopa can wear off for some time. This is referred to as an off episode.  Safinamide is used as an add-on treatment during such episodes.

Additional information

Some common side effects of MAO-B inhibitors include dizziness, headache, confusion, nausea, insomnia, and dyskinesia.

Interactions of MAO-B inhibitors with certain foods and medications are also fairly common. For example, MAO-B inhibitors may interact with antidepressants, selective serotonin reuptake inhibitors (SSRIs), and serotonin-norepinephrine reuptake inhibitors (SNRIs). It is therefore very important to consult a medical professional before using MAO-B inhibitors in order to determine the right dose and frequency of treatment.


Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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