Lack of a rewarding effect and a locomotor-enhancing effect of the selective μ-opioid receptor agonist amidino-TAPA.

Rationale And Objectives: Psychological dependence is one of the worst side effects of morphine. It limits the clinical availability of morphine and non-patient morphine users suffer from addiction. An analgesic, which is more potent than morphine but without the liability of psychological dependence, has long been sought in the clinic.