Interaction between delta 9-tetrahydrocannabinol and morphine on the motor activity of mice

Psychopharmacology (Berl). 1979 May 25;63(2):169-72. doi: 10.1007/BF00429697.


The present experiments dealt the effects of delta 9-tetrahydrocannabinol (THC) on the locomotor activity stimulating action of morphine in mice. In the first series of experiments, the pretreatments of mice by THC in doses up to 20 mg/kg have been found to potentiate the morphine-induced hyperactivity in dose-dependent manner, but higher doses of THC did not produce such an action. In the second series of experiments the dose-response curve of morphine for the motor activity has been found to shift to the left by the pretreatment of mice with 10 mg/kg of THC. These results show a synergism between morphine and THC and suggest that both drugs may share some common site of action.

MeSH terms

  • Animals
  • Dronabinol / pharmacology*
  • Drug Interactions
  • Male
  • Mice
  • Morphine / pharmacology*
  • Motor Activity / drug effects*
  • Time Factors


  • Morphine
  • Dronabinol