Severe venlafaxine poisoning successfully rescued with veno-arterial extracorporeal membrane oxygenation: A case...

Venlafaxine, a serotonin-norepinephrine reuptake inhibitor, is widely prescribed for the treatment of major depressive disorder. At therapeutic dose, it is generally safe, with a low incidence of adverse effects. However, massive venlafaxine ingestion can cause serious cardiotoxicity, leading to life-threatening arrhythmias.

A 31-year-old woman with a history of depression ingested 14.8 g of venlafaxine along with 6 mg of estazolam and 6 mg of flunitrazepam. On admission, 2 hours post-ingestion, she presented only with mild QTc prolongation. At 4 hours post-ingestion, she developed a generalized tonic-clonic seizure. Following endotracheal intubation, intravenous midazolam infusion was initiated and 50 g of activated charcoal was administered via a nasogastric tube. At 15 hours post-ingestion, she developed ventricular tachycardia that rapidly progressed to refractory ventricular fibrillation, which was successfully treated with veno-arterial extracorporeal membrane oxygenation. Toxicological analysis revealed serum venlafaxine and O-desmethylvenlafaxine concentrations 17 µg/mL and 10 µg/mL, respectively, at 15 hours post-ingestion.

In cases of massive venlafaxine ingestion, continuous intensive monitoring, particularly of QTc, is essential for at least 24 hours, even when initial clinical signs are mild. If refractory ventricular arrhythmias occur, prompt initiation of veno-arterial extracorporeal membrane oxygenation should be considered.