Interactions of delta-tetrahydrocannabinol with barbiturates and methamphetamine.

TLDR: The findings suggest that Δ1-THC has sedative or tranquilizing actions, enhancing depressant effects of barbiturates and counteracting toxic effects of methamphetamine stimulation.

Abstract: NIale albino rats were tested for interactions of Δ1-tetrahvdrocannabinol (Δ1-THC), a pure, synthesized compound thought to be the principal euphoric constituent of marihuana, with the depressant action of two barbiturates and with the stimulant action of methamphetamine. In a test of spontaneous motor activity in a photocell arena, Δ1-THC (4 and 16 mg/kg) potentiated the depressant effect of both pentobarbital (10 mg/kg) and barbital (120 mg/kg). The same doses of Δ1-THC also prolonged sleeping time under pentobarbital (30 mg/kg) and barbital (240 mg/kg). Since barbital is not metabolized, interaction with . Δ1-THC is attributable to synergetic depressant actions in the central nervous system rather than inhibition of microsomal enzymes. The higher dose of Δ1-THC (16 mg/kg), which by itself greatly decreased spontaneous motor activity, failed to diminish the stimulant effect of two doses of methamphetamine (0.5 and 2 mg/kg). However, the percentage of animals surviving a toxic dose of methamphetamine (25 mg/kg) was increased by Δ1-THC (4 and 16 mg/kg). The findings suggest that Δ1-THC has sedative or tranquilizing actions. enhancing depressant effects of barbiturates and counteracting toxic effects of methamphetamine stimulation. These interactions with other drugs were found even with a low dose of Δ1-THC (4 mg/kg). which by itself had little effect on spontaneous motor activity.