Kuo-Tai CHEN, You-Ming CHEN, Chien-Chin HSU

Delayed Toxicity of a Patient with Valproic Acid Overdose

Introduction: Nowadays, Valproic acid (VPA) is widely used for the treatment of seizures, mood disorder, schizophrenia, andmigraine prophylaxis. With its extended use, the incidence of acute VPA poisoning is increasing. Though most patients with VPAoverdose may recover with supportive care, delayed toxicity may result in the underestimation of the severity.Case Report: We reported on a case of VPA and benzodiazepine overdoses with two-phase alternations of mental states,and the peak serum VPA level developed 22 h post-ingestion. The patient underwent an emergency tracheal intubation andartificial ventilation for the presence of acute respiratory failure and coma. After two courses of hemodialysis, he recovered toclear consciousness and spontaneous respiration.Conclusion: Toxidromes of VPA poisoning can develop late after acute poisoning. Accordingly, we suggest that all intoxicatedpatients should undergo prolonged observation until the serum VPA level has decreased and the toxidromes have disappeared.Activated charcoal, carnitine, naloxone, and hemodialysis/hemoperfusion are potential regimens to decrease absorption, toreverse the toxidromes, and to enhance elimination for patients with VPA poisoning.

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