Objective: Epilepsy is a devastating neurological disorder with several cognitive or psychiatric comorbidities, including anxiety, autism spectrum disorder, and depressive disorder. It is known that long-term drug treatment in epileptic patients increases the incidence of depression. Thus, patients with epilepsy who later developed depressive symptoms usually require to use of antidepressant medication throughout their epilepsy treatment. However, selective serotonin reuptake inhibitors (SSRIs) derived from antidepressant drugs could have bidirectional effects on seizure activity. This experimental study was designed to determine the impact on the epileptiform activity of escitalopram in a penicillin-induced seizure model.
Method: Administration of penicillin (500 IU, 2.5 μL, intracortical) into the somatomotor cortex of Wistar albino male rats triggered epileptiform activity. Electrocorticography of seizure activity was recorded for 180 min. Escitalopram, at doses of 5, 10, and 20 mg/kg, was administered 30 min after the penicillin injection.
Results: While escitalopram, at doses of 5 and 10 mg/kg, increased the mean spike frequency for 180 min compared with the penicillin group, the 20 mg/kg dose caused a marked increase in the mean spike frequency and amplitude of seizure activity.
Conclusion: The electrophysiological data propose that escitalopram, used for treating depression, has proconvulsant effects in penicillin-induced seizure activity. Therefore, other SSRIs, especially escitalopram, must be used with great care. The mechanism of action needs to be clarified in further detailed studies.