Late-onset seizures associated with quetiapine poisoning.
BACKGROUND
Quetiapine, a second-generation antipsychotic, acts at multiple brain neurotransmitter receptors and has the potential for serious complications. Although seizures have been described in the literature, delayed seizure onset has not been reported. We report the first case of delayed seizures after a significant quetiapine overdose.


METHODS
A 27-year-old female presented to the emergency department following an overdose of approximately 30 g of quetiapine. Twenty-four hours after arrival, the patient had 2 seizures. The patient was then intubated and remained in the ICU for four days. EEG was negative for epileptiform activity. The serum quetiapine levels (MedTox, St. Paul, MN) were 8.67 mg/L on hospital day one and 3.28 mg/L on hospital day three.


CONCLUSIONS
Quetiapine poisoning, with serum levels, associated with seizures has been reported in one prior case. Our case report represents late-onset seizures with serum levels above therapeutic range (>1 mg/L). The serum concentrations of quetiapine in this case were consistent with those in postmortem case reports.
Young
Amy C
AC
Division of Emergency Medicine, UT Southwestern Medical Center, Dallas, TX, USA. acyoung_2000@yahoo.com
Kleinschmidt
Kurt C
KC
Wax
Paul M
PM
D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000097:blood / Q000506:poisoning*; D003422:Critical Care; D003987:Dibenzothiazepines / Q000097:blood / Q000506:poisoning*; D062787:Drug Overdose; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D006801:Humans; D000069348:Quetiapine Fumarate; D012008:Recurrence; D012640:Seizures / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
D000927:Anticonvulsants; D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D000069348:Quetiapine Fumarate