Phenytoin-Induced Paradoxical Seizures and Blood Dyscrasias in a Patient Receiving Rapid Intravenous Infusion: A Case Report

Abstract

Paradoxical seizure is an unusual reaction of seizure aggravation or change in its pattern due to antiepileptics. Decrease in seizure threshold with phenytoin is bound to occur with an increase in serum levels. We herein report a 51-year-old female, who was brought to the intensive care unit with complaints of episodic seizures and frothing. She is a known case of tonic–clonic epilepsy on oral phenytoin 100 mg for past 6 months. Rapid intravenous infusion of 700 mg phenytoin in 100 mL normal saline over a rate of 15 minutes was initiated on admission. This was followed by a sudden abnormality of her baseline blood parameters and an occurrence of paradoxical seizure. The dose of phenytoin was tapered which reversed her condition. The patient was followed up regularly and monitored for fluctuations in her hematological parameters. The mainstay treatment for phenytoin-induced paradoxical seizure and blood dyscrasias is to monitor the patient and dose titration. Dosing of phenytoin remains a challenge for all clinicians which increase the need for such reports.