Impact of Psychotropic drugs on Seizure threshold (P6.311)

To review existing literature regarding the impact of psychotropic medications on seizure threshold.

Psychiatric disorders represent a common comorbidity in epilepsy and require utmost consideration when treating the epileptic population.

Databases such as PubMed, MeSH and Cochrane were screened for cases, case reports, review articles and prospective studies that reported lowering of seizure threshold with use of antidepressants and antipsychotics. Authors and a senior faculty member independently reviewed the extracted data for its validity and relevance. Only articles that specifically discussed lowering seizure threshold in patients with epilepsy were selected. Studies in which the diagnosis of epilepsy was unclear were excluded.

Utilizing the above-mentioned search terms we initially identified a total of 320 articles of which 60, ranged from 1980 to 2016, and were found to meet inclusion criteria. Incident rates reported for TCA were around 3–4% (Imiparamine & amitryptline around 0.01% – 0.06%, while clomipramine and maprotiline around 10%). Duloxetine and other SSRI’s appeared to have anticonvulsant properties at therapeutic doses and an incidence of <0.01% at supra-therapeutic doses. Clozapine among antipsychotics had the greatest cumulative risk of seizures at 10%. Clozapine and Olanzapine were also reported to cause changes on the EEG. Risperidone did not show any increase in seizure even at higher doses.

The drugs with the most propensity to lower seizure threshold included: Bupropion, Imipramine, Clozapine, Olanzapine and Haldol. Relative safer drugs included Selective Serotonin Reuptake Inhibitors & Selective Norepinephrine Reuptake Inhibitors (SSRI/SNRIs), Risperidone and Seroquel. Given the spectrum of psychotropic medications and their impact on the seizure threshold, individual considerations should be given to each patient prior to selecting a psychotropic medication. There is still need for future studies individualizing these drugs along with an intra SSRI comparison to select the safest drugs.

Disclosure: Dr. Bhatti has nothing to disclose. Dr. Dorriz has nothing to disclose.