Prevention of seizure-induced sudden death in a chronic SUDEP model by semichronic administration of a selective serotonin reuptake inhibitor.

DBA/1 mice are a chronically susceptible model of sudden unexpected death in epilepsy (SUDEP) that exhibit chronic audiogenic generalized convulsive seizures (GCSs), leading to death from respiratory arrest (RA) if not resuscitated. Serotonin (5-HT) normally enhances respiration in response to elevated CO(2) levels, which occur during GCSs in humans. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, increase 5-HT availability. We examined whether fluoxetine can block GCS-induced sudden death in DBA/1 mice. Fluoxetine (15-70 mg/kg ip) was administered acutely with seizure induction at 30minutes or semichronically in five daily doses (20mg/kg/day) with induction after 5 days. Acute fluoxetine (45 or 70 mg/kg) significantly reduced the incidence of RA without blocking seizure susceptibility. Semichronic fluoxetine did not block seizures, but significantly reduced seizure-induced RA, which is consistent with effects of SSRIs on respiration in patients with epilepsy [Bateman LM, Li DS,LiN TC, Seyal M. Epilepsia 2010;51:2211-4]. These findings suggest that treatment with SSRIs should be evaluated for reducing the incidence of SUDEP in patients.