Cocaine-stimulus generalization to two new designer drugs: methcathinone and 4-methylaminorex.

Rats were trained to discriminate 8 mg/kg cocaine from saline vehicle for the purpose of examining the stimulus properties of two novel and structurally related drugs of abuse recently confiscated on the illicit market: (+/-)methcathinone and cis(+/-)4-methylaminorex. The stimulus properties of these controlled substance analogs were compared with those of their parent compounds (+/-)cathinone and aminorex, respectively. All agents resulted in cocaine-stimulus generalization with the following rank order of potency: aminorex (ED50 value = 0.8 microM/kg) > methcathinone (1.9 microM/kg) > cathinone (3.7 microM/kg) > 4-methylaminorex (5.2 microM/kg) > cocaine (7.6 microM/kg).