pentazocine ( 30 , 100 , 150 mg/kg i.p . ) aminopyrine ( 15,50 , 100 , 150 mg/kg i.p . ) , phenacetin ( 100,150 , 200 , 250 mg/kg i.p . ) sodium salicylate ( 150 , 200 , 250 mg/kg i.p . ) and other antipyretic analgesics were active in a wide range of doses indicating that this technique is sensitive to the narcotic antagonist and to the weak analgesics as well as to the narcotic analgesics as well as to the narcotic analgesics such as morphine ( 2.5 , 5 , 10 , 15 mg/kg i.p . ) , codeine ( 10 , 20 , 25 , 30 , 50 mg/kg i.p . ) and pethidine ( 5,10 , 15 , 20 , 25 mg/kg i.p . ) .
C0026549
morphine
C0009214
codeine