Severe and Prolonged Paroxetine Intoxication With Delayed Absorption and Extreme Serum Concentrations: A Case Report

Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed antidepressants, known for their relatively safe pharmacological profile and mild symptoms in cases of overdose compared with other antidepressants.In this case report, we describe a near-fatal case of a 70-year-old woman who ingested multiple drugs with suicidal intent, including an unknown quantity of celecoxib 200 mg, clorazepate acid 5 mg, omeprazole 20 mg, and immediate-release paroxetine 30 mg tablets.The patient developed severe serotonin syndrome complicated by acute respiratory distress syndrome (ARDS) and required admission to the intensive care unit (ICU).Because of progressive respiratory deterioration, she required intubation and invasive mechanical ventilation.Serotonin syndrome persisted for an unusually long period, with serum paroxetine concentrations of 4805 µg/L at admission that continued to rise to a maximum of 7824 µg/L on day four, both well above the lethal threshold.Intensive therapeutic interventions aimed at lowering paroxetine concentrations and resolving serotonin syndrome included activated charcoal, whole-bowel irrigation lavage, and rifampicin.Paroxetine concentrations gradually declined and reached the therapeutic range after 16 days.Following further ICU treatment, including prone ventilation and corticosteroids, the ARDS resolved, and the patient was extubated 21 days after ingestion.This case highlights that paroxetine overdose may present more severely than commonly reported in the literature, with delayed and prolonged toxicity, including serotonin syndrome and ARDS.Paroxetine overdose may be life-threatening and underscores the need for close monitoring of serum paroxetine concentrations and timely consideration of activated charcoal and whole-bowel irrigation.