Successful multimodal treatment of venlafaxine overdose-induced catecholamine-refractory shock: a case report

Venlafaxine was the first serotonin/noradrenaline reuptake inhibitor used to treat major depressive disorders. Its overdose can cause cardiovascular toxicity and life-threatening cardiogenic shock. We present the case of a 48-year-old woman who experienced venlafaxine overdose-induced cardiogenic shock. Initial treatment included gastric lavage, blood purification therapy, and ventricular assist device use. The serum venlafaxine concentration was 21.4 μg/mL at 12-24 hr after ingestion, which subsequently decreased to 11.0 and 8.4 μg/mL after 1 and 2 days, respectively. This trend in blood concentration exhibited a biphasic elimination pattern. In addition to venlafaxine-induced cardiotoxicity, the patient exhibited peripheral vascular unresponsiveness to catecholamines. Notably, this vascular dysfunction resolved more rapidly than the cardiotoxic effects. Ultimately, the patient was transferred to a psychiatric ward without sequelae. Although venlafaxine overdose-induced cardiotoxicity has been reported, reports on the unresponsiveness of peripheral blood vessels to catecholamines remain lacking. In cases of venlafaxine overdose-induced cardiogenic shock, both left ventricular function may be impaired and peripheral blood vessels may also be unresponsive to catecholamines. Therefore, rapid initiation of extracorporeal life support and multimodal removal of venlafaxine tailored to the clinical situation may contribute to patient survival.