Certain SSRI medications fail to achieve same selectivity for prevention of SUDEP

Scientists from Southern Illinois University today reported the results of a study evaluating the potential effect of two selective serotonin reuptake inhibitors (SSRI) antidepressant medications in reducing the risk of sudden unexpected death in epilepsy (SUDEP). In a report presented at the American Epilepsy Society's 66th Annual Meeting, the research team found that certain SSRI medications in the study failed to achieve the same selectivity for prevention of SUDEP as fluoxetine, an SSRI they had previously investigated.

In the previous study, the Southern Illinois team demonstrated that the SSRI fluoxetine is effective in blocking SUDEP in an animal model for audiogenic seizures, leading to the possibility of currently available medicines eventually being proven of use in reducing SUDEP risk in persons with poorly controlled seizures. The study they now report was conducted to determine if other SSRIs, fluvoxamine or sertraline, would have the same effect on SUDEP, a currently untreatable condition in humans. (Abstract #1.018) An additional SSRI, paroxetine, was also tested recently.

The investigators tested the effects of fluvoxamine, sertraline and paroxetine in mice subject to seizure-induced, cardio-respiratory arrest at the sound of an electrical bell. Mice that exhibited cardio-respiratory arrest were resuscitated and later treated with one of the trial medications. Each of the susceptible animals was subsequently exposed again to the seizure-inducing sound.

Seizure-induced, cardio-respiratory arrest was significantly reduced by fluvoxamine or sertralinewithin 30-minutes after administration. Paroxetine was not effective until after 24 hours. Susceptibility to audiogenic seizures remained, and susceptibility to seizure-induced cardio-respiratory arrest was observed to occur 24 hours following administration of the trial medications except paroxetine.

Carl L. Faingold, Ph.D., Chairman of the Department of Pharmacology, Southern Illinois University, and lead author of the study, reported that, "The lack of selectivity for blocking the seizure-induced cardio-respiratory response in our study contrasts with the relative selectivity of fluoxetine, which in our previous work has been shown to block this response without affecting seizure severity. The possibility that fluoxetine might prevent SUDEP in patients with uncontrolled seizures should be evaluated."

Source: Southern Illinois University