Potent and selective P2X7 receptor antagonist (IC50 values are 18 and 40 nM for rat and human receptors respectively). Displays selectivity over a variety of P2X and P2Y receptors up to a concentration of 100 μM. Reduces nociception in animal models of persistent neuropathic and inflammatory pain. Also reduces neuroblastoma tumor growth in mice. Purity 98%. MW (observed): 474.55