amitriptyline ( median effective dose [ ed50 ] 1.2 mg per kilogram of body weight ) , imipramine ( ed50 2.3 mg/kg ) , and their demethylated derivatives nortriptyline ( ed50 1.9 mg/kg ) and desimipramine ( ed50 3.2 mg/kg ) are active analgesics as indicated by the mouse writhing assay .
C0002600
amitriptyline
C0028420
nortriptyline