High affinity P2X 3 receptor antagonist (K i values are 36, 82 and 4144 nM for P2X 3 , P2X 1 and P2X 2 recombinant receptors respectively). Shows no activity at P2Y 1 , P2Y 2 and P2Y 11 receptors (IC 50 > 10 μ M). Potently inhibits α , β -meATP-evoked desensitizing currents in rat DRG neurons (IC 50 = 527 nM). Shows antitumor activity against several tumor types.
