Overdose with antiepileptic drugs: the efficacy of extracorporeal removal techniques

Drug overdose is a growing problem among adolescents. Clinical severity depends on the drug and ingested amount, which in some cases may be life-threatening. We present a clinical case of a previously healthy teenage girl who ingested 16.4 g of carbamazepine and 14.5 g of valproic acid. She presented with profound disturbance of consciousness and toxic levels of both drugs, raised in the first hours after the ingestion. She was successfully treated with charcoal haemoperfusion followed by continuous venovenous hemodiafiltration. Overdose with the two drugs separately is common, but there are no reports of intoxication by simultaneous ingestion. High levels of carbamazepine and valproic acid can lead to severe systemic effects and management is made difficult by the absence of specific antidotes. Extracorporeal removal techniques are a good therapeutic option in these cases as they enhance the clearance by reducing the half-life of both drugs thereby preventing serious complications.