Attenuation by glucose of the hyperactivity induced in mice by combined tripelennamine and morphine

The present study examined the effects of glucose on the hyperactivity induced by morphine (10 mg/kg), given alone or combined with the histamine H₁-receptor antagonist tripelennamine (2.5 or 5 mg/kg), in mice of the CD-1 strain. In the first experiment, glucose (50, 100, 250, or 500 mg/kg) had no significant effect on spontaneous locomotor activity, but at the dose of 100 mg/kg significantly reduced morphine-induced hyperactivity. In the second experiment, the administration of glucose (50 or 100 mg/kg) was also able to attenuate the locomotor stimulation induced by combined tripelennamine and morphine. The results are consistent with the hypothesis that glucose may inhibit opiate functions and indicate that glucose may exert an inhibitory action even on the central action of combinations of opiate and antihistaminic agents, drug combinations able to produce additive euphoric effects in humans.