Highly selective, water-soluble, human A 2B adenosine receptor antagonist. K i values are 53.4, > 10000 and > 10000 nM at human A 2B , A 1 and A 3 receptors respectively. Also selective versus rat A 1 and A 2A receptors (K i values are 2200 and 24000 nM respectively). Produces potent analgesic effects in vivo .