ICD-10 Specific code G40.2: Localization-related (focal)(partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures

Brivaracetam displays a high and selective affinity for synaptic vesicle protein 2A (SV2A), a transmembrane glycoprotein found at presynaptic level in neurons and in endocrine cells. Although the exact role of this protein remains to be elucidated it has been shown to modulate exocytosis of neurotransmitters.

Eslicarbazepine and its metabolites stabilise the inactivated state of voltage-gated sodium channels, precluding their return to the activated state and thereby preventing repetitive neuronal firing. Therefore eslicarbazepine is indicated as adjunctive therapy in adults with partial-onset seizures with or without secondary generalisation.

Lacosamide is a functionalised amino acid. The precise mechanism by which lacosamide exerts its antiepileptic effect in humans remains to be fully elucidated.

Levetiracetam, is a pyrrolidone derivative, chemically unrelated to existing antiepileptic active substances. Levetiracetam induces seizure protection in a broad range of animal models of partial and primary generalised seizures without having a pro-convulsant effect. The primary metabolite is inactive.

Midazolam is a derivative of the imidazobenzodiazepine group. The free base is a lipophilic substance with low solubility in water. The basic nitrogen in position 2 of the imidazobenzodiazepine ring system enables the active ingredient of midazolam to form water-soluble salts with acids.

The pharmacological activity of oxcarbazepine is primarily exerted through the metabolite (MHD). The mechanism of action of oxcarbazepine and MHD is thought to be mainly based on the blockade of voltage-sensitive sodium channels.

Perampanel is a first-in-class selective, non-competitive antagonist of the ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor on post-synaptic neurons. Glutamate is the primary excitatory neurotransmitter in the central nervous system and is implicated in a number of neurological disorders caused by neuronal overexcitation. The precise mechanism by which perampanel exerts its antiepileptic effects in humans remains to be fully elucidated.

Phenytoin is effective in various animal models of generalised convulsive disorders, reasonably effective in models of partial seizures but relatively ineffective in models of myoclonic seizures. It appears to stabilise rather than raise the seizure threshold and prevents spread of seizure activity rather than abolish the primary focus of seizure discharge.

Primidone is an anticonvulsant. Although the precise mode of action of primidone is unknown, in common with other anticonvulsants, effects on the neuronal membrane particularly with respect to alteration of ionic fluxes are likely to play a fundamental role.

Tiagabine is an anti-epileptic drug. Tiagabine is a potent and selective inhibitor of both neuronal and glial GABA uptake, which results in an increase in GABAergic medicated inhibition in the brain.

Topiramate is classified as a sulfamate-substituted monosaccharide. The precise mechanism by which topiramate exerts its antiseizure and migraine prophylaxis effects are unknown.

Zonisamide is a benzisoxazole derivative with antiepileptic and anticonvulsant activity. The mechanism of action of zonisamide is not fully elucidated, but it appears to act on voltage-sensitive sodium and calcium channels, thereby disrupting synchronised neuronal firing, reducing the spread of seizure discharges and disrupting subsequent epileptic activity.