The role of AMPA receptors and their antagonists in status epilepticus

Status epilepticus (SE) is typically defined as a prolonged self-sustaining seizure or repeated seizures showing an incomplete recovery between them. SE represents a medical emergency often associated with significant disability, morbidity, and mortality. Despite the clinical impact, the mechanisms underlying the transition from self-limited seizures to protracted, medically refractory seizures are not completely understood. About 40% of patients in established SE are refractory to antiepileptic drugs (first-line treatment); therefore, there is a need for more efficacious drugs. In this review, we focused on the current knowledge about the involvement of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors during SE, the preclinical efficacy of its antagonists, and the currently published clinical studies involving drugs with this mechanism of action. We carried out an extensive literature search to recognize experimental and clinical articles both on AMPA receptors and AMPA antagonists and SE. Recently, the role of AMPA receptors during and after SE has become clearer, and it is now widely accepted that early changes occur in the initial stages and probably contribute both to the maintenance of SE and to its refractoriness to treatment. The therapeutic potential of AMPA receptor inhibition has been sustained by studies in which AMPA receptor antagonists have been shown to terminate seizures in several SE animal models. To date, promising, but limited, data in humans support the use of AMPA receptor antagonists in patients with SE. AMPA receptor antagonists could become a new therapeutic option in patients with established SE when the first trials with second-line agents have failed or probably even better after failure of benzodiazepines as a second-line option.