Comparative activity of delta9-tetrahydrocannabinol, diphenylhydantoin, phenobarbital and chlordiazepoxide on electroshcok seizure threshold in mice.

delta9-Tetrahydrocannabinol (THC) was compared with diphenylhydantoin (DPH), phenobarbital (PB) and chlordiazepoxide (CDP) using two electroshock procedures to determine anticonvulsant activity in mice, i.e., electroshock seizure threshold (EST) and the reduced EST caused by hyponatremia (injection of isotonic glucose). Using doses of each drug which were ineffective against MES, only CDP (10.0 mg/kg) was able to raise the EST by 20%. The lowered EST due to hyponatremia was reveresed by al four drugs. In these tests latency to convulsions and lethality associated with electroshock were more sensitive to THC.