CGS-15943 is a drug which acts as a potent and reasonably selective antagonist for the adenosine receptors A<sub>1</sub> and A<sub>2A</sub>, having a K<sub>i</sub> of 3.3nM at A<sub>2A</sub> and 21nM at A<sub>1</sub>. It was one of the first adenosine receptor antagonists discovered that is not a xanthine derivative, instead being a triazoloquinazoline. Consequently, CGS-15943 has the advantage over most xanthine derivatives that it is not a phosphodiesterase inhibitor, and so has more a specific pharmacological effects profile. It produces similar effects to caffeine in animal studies, though with higher potency.