Valproate-induced hyperacute hyperammonemic coma in a patient with hypocarnitinemia

Area of Science:

• Neurology
• Pharmacology
• Metabolic Disorders

Background:

• Valproate is a widely used antiepileptic and mood-stabilizing drug.
• Hyperammonemic coma is a rare but serious adverse effect of valproate therapy.
• Previous reports indicate this complication can manifest days to years after valproate initiation.

Observation:

• We describe a unique case of a patient who developed hyperammonemic coma rapidly after starting valproate therapy.
• The patient was found to have an underlying plasma carnitine deficiency.

Findings:

• This case highlights that valproate-associated hyperammonemic coma can occur within hours of drug initiation.
• Plasma carnitine deficiency is a potential risk factor for rapid-onset valproate-induced hyperammonemic coma.

Implications:

• Clinicians should consider carnitine deficiency in patients presenting with unexplained hyperammonemia during valproate therapy.
• Early recognition and management of hyperammonemia are crucial for patient outcomes.
• This case expands the understanding of the temporal relationship and potential risk factors for valproate-induced hyperammonemic coma.