PROBLEM TO BE SOLVED: To provide novel agents useful for the treatment of diseases by inhibition of Serotonin type 3 (5-HT3) receptors such as emesis, pain, drug addiction, neurodegenerative and psychiatric disorders, and GI disorders.SOLUTION: The present invention provides a 5-HT3 receptor antagonist that is a compound represented by formula (I) and including an azo bicyclo ring and a pyridine or pyrazole ring.SELECTED DRAWING: None
5-HT3 RECEPTOR ANTAGONISTS