the narcotic analgesics morphine ( 0.1 , 1.0 and 5 mg/kg ) , meperidine ( 1.0 and 2.0 mg/kg ) , methadone ( 1.0 mg/kg ) and codeine ( 5.0 and 10.0 mg/kg ) greatly reduced ach release.3 .
C0026549
morphine
C0009214
codeine