What you need to know about A2A Receptor Antagonists as New Drugs for Parkinson's Disease Treatment

There has been tremendous interest in the adenosine A2 receptor as a drug-able target to treat the symptoms of Parkinson's disease.  Here are the important bullet points about this drug strategy.

- There are a bunch of adenosine A2A receptors located on the outside of nerve cells in the brain that are referred to as neurons

- Many of these receptors sit next to dopamine receptors

- You may be able to activate the dopamine receptor, or alternatively block the adenosine A2 receptor to treat the disabling symptoms of Parkinson’s disease

- There is a hope these drugs may allow practitioners to decrease the dosages of other PD drugs and to reduce side effects-- however this has not be proven

- Istradefylline is an adenosine A2A receptor antagonist that has displayed  mild beneficial effects on wearing off and on motor fluctuations

- It is not FDA approved but is approved in Japan

- Biotie is a company that has another A2A receptor antagonist tozadenant (SYN115) and some very preliminary results show improvements in off time

- Merck has a A2A receptor antagonist called Preladenant

- Three phase III trials did not provide evidence for efficacy of Preladenant over placebo pill

- Vipadenant (BIIB014) and ST-1535 among several other A2A receptor antagonists remain under investigation

- An important thing for patients to keep in mind is that caffeine (coffee) stimulates the adenosine A2A brain receptor, and this may be responsible for some benefits in Parkinson's disease patients

See more at Dr. Okun's NPF's What's Hot in Parkinson's Disease column