Transient Arginine Vasopressin Deficiency Induced by Valproic Acid Intoxication: A Case Report

Valproic acid is commonly used for treating seizures and psychiatric disorders. Valproic acid is a common anticonvulsant drug causing overdose for suicidal purposes. The most common symptom of valproic acid poisoning is central nervous system damage. Most cases result in mild to moderate drowsiness, while in severe cases, fatal cerebral edema and coma have been reported. Other complications include respiratory depression, hepatotoxicity, thrombocytopenia, and multi-organ failure resulting in circulatory collapse. Herein, we present a case of a 42-year-old woman who ingested an overdose of 600 mg nitrazepam, 50 mg olanzapine, and 35,600 mg valproic acid. The maximum daily doses for nitrazepam, olanzapine, and valproic acid are 15, 20, and 1200 mg, respectively. This overdose led to reversible arginine vasopressin (AVP) deficiency as a rare but significant complication. The deficiency led to polyuria with dilute urine, which was effectively suppressed by AVP administration. This case highlights the potential for reversible AVP deficiency as a rare but significant complication of valproic acid overdose. Early diagnosis and appropriate management are crucial for favorable outcomes.