Severe recurrent serotonin syndrome with late-onset seizures following a single escitalopram overdose ingestion: A case report

Severe serotonin syndrome (SS) secondary to escitalopram is not commonly reported. We present the first case of severe recurrent SS with late-onset seizures following a single escitalopram overdose ingestion. A 17-year-old girl was referred to the Emergency Department (ED) after allegedly ingesting about 330 mg of escitalopram due to suicidal ideation. She developed mild serotonin syndrome (tremors, hyperreflexia) and prolonged QTc of 620 ms, which resolved within 24 h, and she was discharged after about 48 h of observation. In less than 24 h, she was brought to the ED by her mother due to reduced responsiveness and jerky movement of all limbs. There was no repeated ingestion of escitalopram. On arrival, her Glasgow coma scale (GCS) was full but tachycardic, and she had a temperature of 38 °C, and prolonged QTc (610 ms). In the ED, the patient had myoclonic jerks and fitted (general tonic-clonic) 3 times before being intubated for airway protection. Cyproheptadine was started in the ED as SS symptoms persisted despite multiple diazepam boluses and heavy sedation with midazolam, morphine, and propofol. The serotonin syndrome fully resolved after five days. Changes in escitalopram’s pharmacokinetics following a massive overdose are unknown. Severe recurrent SS and late-onset seizures can occur up to 72 h following a significant escitalopram overdose ingestion, and the patient should be closely monitored for a longer duration. • Recurrent severe serotonin syndrome can occur with escitalopram overdose. • Late-onset seizure can occur up to 72 h post-escitalopram overdose. • Extended monitoring is necessary in significant escitalopram overdoses due to potential delayed effects.