conditions that produced the largest increase in sensitivity to the discriminative stimulus effects of naltrexone ( 32.0 mg/kg of morphine 24 hr before the session ) also increased sensitivity to the discriminative stimulus effects and rate-decreasing effects of naloxone , but did not affect the discriminative stimulus effects of diprenorphine , nalorphine or morphine .
C0027360
naltrexone
C0027358
naloxone