Valproate Induced Delirium due to Hyperammonemia in a Case of Acute Mania: A Diagnostic Dilemma

Divalproex sodium is commonly used drug to treat variety of psychiatric and neurological disorders. Hyperammonemia is infrequent adverse affect of treatment with divalproex sodium. It needs high degree of clinical suspicion or else can lead to delirium of non hepatic origin in some group of patients and to medication errors or even death. We hereby report a case of mania who developed hyperammonemia with normal sodium valproate levels and liver function tests where delirium lead to diagnostic and medication errors. Withdrawal of divalproex sodium led to clinical recovery but delirium prolonged his hospital stay. This case report cautions the clinicians about hyperammonemia as the uncommon side effects and emphasizes the need of doing blood ammonia testing in patients treated with divalproex sodium where recovery is halted or clinical condition worsens despite normal liver function test and EEG.