Hypothyroidism exacerbating valproate induced hyperammonemic delirium, an unknown clinical concern: Short communication

From the literature reviews, valproic acid (VPA) induced hyperammonemia is a commonly adverse event and usually asymptomatic. VPA is a well-tolerated and an effective agent for the treatment of epilepsy, bipolar disorder, schizoaffective disorder, off-lable use for the impulsive control problems and etc. However, several case reports have indicated that VPA may induce serious symptomatic hyperammonemia and even lethal. Based on the analysis of susceptible patients, several possible mechanisms and risk factors have been proposed to identify the patients at risk. Nevertheless, the co-morbid hypothyroidism patients suffer from the more tentative risk in the vulnerability of VPA induced hyperammonemia. Few researches focused on this clinical phenomenon and underlying mechanism of action. In this short communication, we aimed to review the articles about the VPA induced hyperammonemia. We also summarized the risk factors of hypothyroidism related to such clinical condition. We especially focused on the neuropsychological side effects such as consciousness disturbance or delirium. We found out these patients mainly female. Most of them didn’t suffer from the underlying psychiatric disorder. In addition, only one case report reveals that the merely subclinical hypothyroidism without any treatment would have the risk of VPA induced hyperammonemia and the consequent delirium.