NCIt definition : A long-acting barbituric acid derivative with antipsychotic property. Phenobarbital
binds to and activates the gamma-aminobutyric acid (GABA)-A receptor, thereby mimicking
the inhibitory actions of GABA in the brain. The activation effects of the phenobarbital-receptor-ionophore
complex include increased frequency of chloride channel openings, membrane hyperpolarization
and ultimately synaptic inhibition and decreased neuronal excitability. In addition,
this agent inhibits glutamate induced depolarization.;
Alternative definition : NCI-GLOSS: A drug that is used to treat seizures and as a sedative. It is being studied
in the treatment of diarrhea and for its ability to increase the antitumor effect
of other therapies. It belongs to the family of drugs called barbiturates.;