Highly selective, water-soluble, human A2B adenosine receptor antagonist. Ki values are 53.4, > 10000 and > 10000 nM at human A2B, A1 and A3 receptors respectively. Also selective versus rat A1 and A2A receptors (Ki values are 2200 and 24000 nM respectively). Produces potent analgesic effects in vivo.