Definition

An orally bioavailable synthetic analog of the neuroactive steroid allopregnanolone and positive allosteric modulator of the gamma-aminobutyric acid (GABA)-A receptor, with anxiolytic, sedative, antidepressant and anticonvulsant activities. Upon oral administration, ganaxolone specifically targets and binds to the allosteric sites of the synaptic and extrasynaptic GABA-A receptor-chloride ionophore complex in the central nervous system (CNS). This leads to an increase in the opening of chloride channels, membrane hyperpolarization, increases the inhibitory effect of GABA on the CNS, and inhibits neurotransmission. This blocks seizure propagation and elevates seizure thresholds.