Barbiturate anticonvulsants 

Barbiturate anticonvulsants are a group of drugs derived from barbituric acid and they act by suppressing activity of the central nervous system. Barbiturate anticonvulsants enhance the action of GABA, which is an inhibitory neurotransmitter, and inhibits initiation of discharge that would start the seizure. Barbiturates facilitate GABA-mediated opening of chloride channels and increases effectiveness of GABA.

Barbiturates are used to treat all types of seizures except absence seizures.

Barbiturates approved by the US Food and Drug Administration (FDA) for clinical use include phenobarbital, methohexital, butalbital, pentobarbital, primidone, and amobarbital. Various barbiturates have been either discontinued or substituted with benzodiazepines.

Depending on their mechanism of action, anticonvulsant drugs in clinical use may be divided into three groups: those drugs which facilitate gamma-aminobutryic acid (GABA)ergic neurotransmission; those which block neuronal ion channels; and those whose mechanism of action is unresolved.