adenosine receptor agonist adenosine receptor agonist an adenosine receptor agonist is a drug which acts as an agonist of one or more of the adenosine receptors. examples include the neurotransmitter adenosine, its phosphates, adenosine monophosphate (amp), adenosine diphosphate (adp), and adenosine triphosphate (atp), and the pharmaceutical drug regadenoson. list of adenosine receptor agonists atl146e (a2a selective) pd81,723 (a1 allosteric enhancer)