Hyperammonemia Associated With Valproic Acid Use in Elderly Psychiatric Patients

Valproic acid (VPA) is associated with hyperammonemia; however, little is known about this phenomenon in the geriatric psychiatric population. Of 12 such patients prescribed VPA, 83.3% had elevated ammonia. This occurred in the absence of elevated liver enzymes, and there was no association of VPA serum-level to hyperammonemia.