Opiate dependence alters central reward of nalbuphine or pentazocine plus tripelennamine.

The threshold lowering effects of the coadministration of tripelennamine plus nalbuphine or tripelennamine plus pentazocine on the threshold for rewarding electrical intracranial stimulation, a model of drug-induced euphoria, was determined in rats physically dependent to morphine. Although tripelennamine plus nalbuphine had threshold-lowering effects similar to tripelennamine plus pentazocine in non-opiate-dependent subjects, tripelennamine plus nalbuphine failed to lower the threshold for rewarding stimulation in morphine-dependent animals. To the extent that these data may be applied to human addicts, it suggests that opiate-dependent addicts are unlikely to use the combination of tripelennamine plus nalbuphine but are likely to use tripelennamine plus pentazocine.