Antipsychotics and seizures: Higher risk with atypicals?

Abstract

Our results show that SGA may pose a higher risk of seizures than FGA, mainly, but not only due to clozapine. This is line with recent studies suggesting that some SGA carried a higher average risk of electroencephalographic abnormalities than many FGA. Nonetheless, It is well known that spontaneous reports do not allow strong inferences about adverse drug effects, because differences in reporting fractions by time, drug or type of event are difficult or even impossible to distinguish from differences in the occurrence rates of adverse events. Still, we consider that the possibility of SGA carrying a higher risk of seizure induction than FGA warrants further research.

Comparative Analysis of the Treatment of Chronic Antipsychotic Drugs on Epileptic Susceptibility in Genetically Epilepsy-prone Rats

“…1b, 2, 3a). Our data are in agreement with that observed in human therapy where haloperidol is one of the agents with the least seizure-induction activity among antipsychotics [8].…”

“…1a, b; 2; 3a, c). The latter data are partially in contrast with that observed in human therapy where risperidone is an agent with the lowest seizure induction activity among APs [8]. However, a previous clinical study indicated that risperidone overdose is able to induce seizures [87].…”

“…It is generally accepted that APs can lower seizure threshold or provoke seizures [3,8,17]. Despite the fact that APs show efficacy in the treatment of psychosis, several differences exist in their mechanisms of action, which might differentially contribute to their effects on seizures.…”

“…Most neuroleptics can lower seizure threshold and increase the chance of seizure occurrence [3,[7][8][9]. Furthermore, a strong link exists between epilepsy and psychiatric disorders; it is known that such comorbidity exists; many epileptic patients have psychiatric disorders; and, conversely, depressed patients have a higher risk of becoming epileptic [10][11][12][13][14].…”

“…Previous reports indicated that, among the conventional APs, the clinical incidence of seizures during treatment with chlorpromazine was 1.25 % (10/800 patients) [15], whereas haloperidol rarely induces clinical seizure [16]. Furthermore, the clinical incidence of seizures during treatment with atypical APs was 2.89 % (41/1418 patients) for clozapine, 2.34 % (28/1196 patients) for zotepine, 0.88 % (22/2500 patients) for olanzapine, 0.75 % (18/2387 patients) for quetiapine, and 0.35 % (9/2607 patients) for risperidone [3,[7][8][9]. However, the above data are largely based on studies that were not adequately controlled [3, 7-9, 15, 16].…”