Unveiling Valproate induced Hyperammonaemia – Clinical insights from a case series in Psychiatric inpatient setting

Valproate is an agent commonly used for its antiepileptic properties, but in psychiatry it is used for its mood stabilising properties.Valproate-induced hyperammonemic encephalopathy (VHE) is rare but potentially life-threatening complication that can occur even at therapeutic drug levels and with normal liver function. Here, we present a series of ten cases, eight males and two females who got admitted to a tertiary health care centre and developed acute-onset drowsiness, nausea, and lethargy within 2-16 days of initiating valproate therapy. All patients had normal liver function tests but significantly elevated serum ammonia levels.Prompt discontinuation of Valproate and administration of lactulose helped reverse the elevated serum ammonia levels. None of the patients who presented withhyperammonaemia progressed to VHE. This highlights the idiosyncratic nature of VHE, and the need for watchfulness in patients on Valproate. Clinicians should monitor for unexplained mental status changes, particularly when accompanied by gastrointestinal symptoms, and promptly assess serum ammonia levels. Failure to promptly recognize and address hyperammonaemia drastically increases the risk of severe, potentially life-threatening complications like VHE. Early diagnosis and prompt intervention are essential to mitigate this risk and avoid progression to the highly fatal stage of encephalopathy.