Abstracts

RATIONALE: Oral valproic acid (VPA) is usually well tolerated but may produce encephalopathy, liver failure, thrombocytopenia, increased bleeding times and insulin resistance. Intravenous VPA (IV-VPA) may be administered quickly and safely but its pattern of use and outcome in hospitalized and presumably very ill patients is not described. METHODS: We identified all patients, at our tertiary care hospital who received IV-VPA during the years 1998 and 1999. Of 142 patients identified, 125 were adults and 17 were under the age of 18. Thus far, 78 of the adult and 14 of the pediatric charts have been retrieved. RESULTS: Of the charts reviewed, indication for use was seizure control in 76 of 78 adults and all 17 children. All children were over the age of two. Almost all use was on the neurology service or with a neurology consultant. IV-VPA was used to treat status epilepticus in 20 adults and 5 children(2 absence status). VPA was a new drug for 42 adults and 6 children. IV-VPA was loaded in 31 and 1, bolused for level in 14 and 6, and used for maintenance in 33 and 7 adults and children, respectively. Median loading dose was 20 mg/kg and 10 mg/kg in adults and children, respectively. Serum levels below 50 ?g/ml were obtained in 30% of adults. Adverse events attributed to IV-VPA included encephalopathy (n=2). One of these, an adult treated for absence status, went into a coma and developed a burst suppression on EEG that evolved to very low voltage with eventual recovery off IV-VPA. One adult developed encephalopathy with diffuse high voltage delta on EEG. A third adult developed worsening encephalopathy of unknown cause temporally related to IV-VPA but had support withdrawn and died without demonstration of reversibility with IV-VPA cessation. Five other deaths occurred with none considered IV-VPA related. No alterations of platlets, bleeding time, liver function or glucose of significance were attributed to IV-VPA. CONCLUSIONS: Our hospital based experience indicates that IV-VPA is generally safe but is often under-dosed in ill patients at risk for seizures. It's use is uncommon in pediatrics. Encephalopathy, while infrequent, needs to be considered in ill patients who fail to improve mental status.