Valproic acid-induced hyperammonemia and minimal hepatic encephalopathy prevalence among psychiatric inpatients.

Background: Our purpose was to evaluate the relationship between valproic acid (VPA)-induced hyperammonemia (HA) and the prevalence of minimal hepatic encephalopathy (MHE) cognitive impairment among psychiatric inpatients.

Methods: Fifty-two psychiatric inpatients prescribed VPA were tested for MHE impairment after achieving steady-state VPA and ammonia concentrations during hospitalization between December 2013 and June 2014. The relationship between steady-state VPA and ammonia concentration was tested by correlation coefficient.