Anticonvulsant drug antagonism of delta9tetrahydrocannabinol-induced seizures in rabbits.

A population of New Zealand White rabbits exhibit behavioral convulsions when given low doses of psychoactive cannabinoids of marijuana. Carbamazepine, diazepam and phenytoin were most effective in blocking these convulsions caused by delta9tetrahydrocannabinol (delta9THC). Phenobarbital and ethosuximide also blocked convulsions but only at toxic doses. Cannabidiol was effective in blocking convulsions when given concurrently with, but not prior to delta9THC.