This last point is critical because it can delay VHE identification and treatment or worse, result in misdiagnosis with accompanying continuation or escalation of VPA dosing as has initially occurred in Mr. D’s case. Similar concerns have been raised2,5 and occurred,5,19 which is not surprising given the frequency of VPA use for psychiatric conditions and symptoms.
Providers should have a low threshold for checking an ammonia level in clinical scenarios that involve any alteration in mental status that may resemble delirium in psychiatric patients treated with valproate. From a preventative perspective, it may be prudent to avoid valproate in psychiatric patients with known VHE risk factors. Either way, promotion of VHE awareness and detection across medical disciplines is paramount.