A muscarinic acetylcholine receptor antagonist (Kis = 7.55, 22.6, 1.42, 8.86, and 2.63 nM, respectively, for recombinant human M1-M5 receptors); binds to isolated guinea pig bladders (Kb = 0.813 nM) and inhibits ACh release from isolated rat bladders (IC50 = 0.747 nM); reduces urine volume in orally water-loaded rats from 10-300 UG/kg