one group ( n = 9 ) was pretreated with either naloxone ( 2.0 mg/kg iv bolus with 1.7 mg/kg.h ; n = 6 ) or naltrexone ( 2.0 mg/kg iv bolus with repeat bolus of 1.0 mg/kg at 1 , 3 and 5 h ; n = 3 ) and the second group ( n = 10 ) received no opiate antagonist .
C0027358
naloxone
C0027360
naltrexone