The Poison Review

LIFE-THREATENING SODIUM VALPROATE OVERDOSE: A COMPARISON OF TWO APPROACHES TO TREATMENT Licari E et al. Crit Care Med 2009;37:3161-3164.

Abstract

This paper describes two similar cases of sodium valproate (VPA) overdose:  both patients were young women who ingested 16 grams of VPA, and required intubation in the emergency department.  The first patient was treated with supportive care alone, and went on to develop seizures and cerebral edema.  She recovered after 11 days in the intensive care unit.  The second patient underwent hemodialysis, and was discharged to the ward from in ICU on day 3.  The authors conclude that their observations in these two cases support the need for early hemodialysis in patients with severe sodium valproate overdose.

This may be a stretch, but the paper does reinforce the notion that hemodialysis is an option in severe VPA overdose.  Most cases will respond to supportive care alone.  However, VPA overdose can be life-threatening, and increasing drug clearance by hemodialysis may be in some cases a reasonable plan.  As the authors note, although at therapeutic levels VPA is largely )~ 90%) protein bound, in overdose the binding sites quickly become saturated, and amounts of free drug can rapidly increase.  This fact makes hemodialysis viable.  Whether to proceed with that procedure will remain somewhat a question of therapeutic style and philoslphy.