SSRIs (selective serotonin reuptake inhibitors) may prolong seizures

SSRIs (selective serotonin reuptake inhibitors), particularly when taken long term, can modify the brain in ways that may complicate treatment for other conditions. A study just published in Clinical Neurology and Neurosurgery offers evidence that SSRIs prolong epileptic seizures. The authors state:

"Selective serotonin reuptake inhibitors (SSRIs) are often used in the treatment of depressive disorders in patients with epilepsy. Pro- and anti-convulsive effects of SSRIs are discussed controversially. The aim of this study was to investigate a possible impact of SSRIs-treatment on duration of EEG and clinical features in epilepsy patients."

They examined EEG data from 162 patients with focal epileptic seizures, comparing 11 patients who had 19 complex focal seizures (CFSs) and 16 secondary generalised tonic-clonic seizures (sGTCSs) treated with SSRIs (SSRIs+) to 13 patients without SSRIs-treatment (SSRIs-) the duration of seizure components on EEG. Actual seizure (ictal) activity was clearly prolonged in the SSRIs group:

"Ictal EEG duration of both, CFSs and sGTCSs, was significantly longer in SSRIs+ patients than in SSRIs- patients. No significant difference was found between convulsive phase duration of sGTCSs as well as duration of postictal EEG suppression after sGTCSs in both groups."

Clinical note: this suggests that SSRIs may modify the brain's regulation of excitability in ways that can have adverse consequences. Considering the importance of thresholds of excitability this may have significance for a wide range of conditions besides ictal disorders. The authors conclude:

"Seizures last significantly longer in patients with epilepsy and SSRIs as co-medication. A causative role of SSRIs in ictal activity has to be explored in prospective studies."