More than a dozen Parkinson’s therapies have been approved in the past five years. These treatments work in different ways to ease symptoms. Many are familiar with a common drug target: dopamine, the brain chemical that is lost in Parkinson’s disease. Here we introduce another target, the adenosine pathway. One approved treatment targets this pathway and other studies have highlighted its role in lowering Parkinson’s risk.

What is adenosine? 

Adenosine is a chemical found in all human cells. In the brain, it helps a cell respond to other brain chemicals such as dopamine. It does this through receptors: structures on a cell’s surface where interaction occurs. The adenosine A2A receptor interacts with dopamine.

Why are scientists studying adenosine in Parkinson’s? 

Dopamine controls movement. Adenosine slows movement and becomes more active as Parkinson’s progresses, so targeting the A2A receptor may help improve movement when combined with dopamine-replacement therapy such as levodopa (Sinemet).

What therapy targets the adenosine pathway? 

In 2019, the U.S. Food and Drug Administration approved Nourianz (istradefylline) for the treatment of “off” episodes in Parkinson’s. Nourianz is an antagonist (blocker) for the A2A receptor. It doesn’t allow adenosine to slow movement.

“Off” episodes are when symptoms come back between doses of Parkinson’s medication. Long-term disease or levodopa use can contribute to “off” episodes.

Learn more about “off” episodes’.

What else impacts the adenosine pathway? 

Exercise and caffeine also block activity of the A2A receptor. Some studies have shown that people who drink caffeine and exercise may have lower Parkinson’s risk (or delayed onset with exercise). Understanding more about these connections could lead to better treatments and strategies to slow or stop disease.

Please note: No therapies, including those targeting the A2A receptor, have been proven to prevent Parkinson’s disease. Talk to your doctor before adding caffeine or exercise to your treatment regimen.

Article Source: The Michael J. Fox Foundation for Parkinson’s Research