The exact mechanism of anticonvulsant effect is unknown but does not involve inhibitory and excitatory neurotransmission. Stereo-selective binding of Levetiracetam was confined to synaptic plasma membranes in the central nervous system with no binding occurring in peripheral tissue. Studies show that levetiracetam affects intraneuronal Ca levels by partial inhibition of N-type Ca currents and by reducing the release of Ca from intraneuronal stores; facilitates GABA-ergic inhibitory transmission through displacement of negative modulators; reduces delayed rectifier K current; and/or binds to synaptic proteins which modulate neurotransmitter release.