Valproic Acid Overdose: Case Report and Literature Review

Simultaneous, Dual Continuous Venovenous Haemodiafiltration as Salvage Therapy for Severe Sodium Valproate Intoxication

Sodium valproate overdose leads to CNS depression, cerebral oedema, and severe metabolic acidosis in cases of severe toxicity. Extracorporeal removal, specifically through intermittent haemodialysis, is recommended, though not always tolerated by or accessible to haemodynamically unstable patients in intensive care units. We present a case of a male in his mid-twenties presenting following a massive, intentional overdose of 13 g of sodium valproate over 7 hours, with an initial valproate blood concentration of 975 μg/ml (normal 50-100 μg/ml). He was hypoxic and severely acidotic on arrival and was given fluids and L-carnitine according to TOXBASE guidelines. This resulted in only marginal improvement to his acidosis. Once transferred to our intensive care unit, the patient was started on inotropic support followed by continuous venovenous hemofiltration (CVVHDF) at the maximum effluent rate of 60 ml/kg/hr. Due to his persisting metabolic acidosis and worsening hyperlacataemia, dual CVVHDF was started by adding another filter in series after 26 hours, increasing the maximum effluent rate to 96 ml/kg/hr. The patient remained on dual CVVHDF for 31 hours, during which his acidosis and lactate showed considerable improvement, and he was subsequently stepped down to single-filter CVVHDF for a further 20 hours until complete resolution of his acidosis. This case report recognises dual CVVHDF as a viable salvage therapy for severe sodium valproate overdose by facilitating the achievement of a higher effluent flow rate compared to what can be accomplished with single-filter CVVHDF.

Rescue strategies for valproic acid overdose poisoning: Case series and literature review

Valproic acid (VPA) is a wide-ranging anti-epileptic medication that primarily affects bipolar disorder, mania, and migraine. The leading causes of mortality associated with acute poisoning from VPA are nervous system toxicity, drug-induced shock due to encephalopathy from hyperammonemia, as well as acute liver and kidney failure, and respiratory depression that contribute to hemodynamic instability. Treatment of acute VPA poisoning primarily involves in vitro elimination methods, including hemoperfusion (HP), hemodialysis, and hemofiltration, as well as drug remedies such as L-carnitine and meropenem. Nonetheless, there are conflicting opinions regarding drug usage. This article details the three cases of acute poisoning from VPA. The fundamental approach to treatment employs HP assisted by blood concentration monitoring to alleviate shock and stabilize hemodynamics. This investigation presents guidance for the treatment and management of acute poisoning with VPA in clinical settings.