Oxcarbazepine

The exact mechanism through which oxcarbazepine and its active metaoblite, MHD, exert their anti-epileptic effects is unclear, but is thought to primarily involve the blockade of voltage-gated sodium channels. The opening and closing of sodium channels allows for the propagation of action potentials along neurons - in epilepsy, these action potentials can occur in excess of that required for normal function, and the repetitive and pathological firing of these action potentials leads to seizure activity. Both oxcarbazepine and MHD are thought to inhibit seizure activity by binding to the inactive state of voltage-gated sodium channels, thus prolonging the period in which the receptor is unavailable for action potential propagation. This helps to stabilize hyperexcited neuronal membranes, inhibit repetitive neuron firing, and prevent the spread of seizure activity within the CNS without affecting normal neuronal transmission.

Increased potassium conductance and modulation of voltage-activated calcium channels is also thought to play a role in the anti-seizure activity of oxcarbazepine. Inhibition of glutamatergic activity was thought to contribute to oxcarbazepine's activity, but this effect could not be replicated in vivo.