Abstract
Sodium valproate (VPA) is a first-line anti-epileptic drug commonly used in clinical practice, many factors affect the blood concentration of VPA. This study aimed to determine the reasons for low serum levels of Sodium valproate (VPA) in intensive care unit (ICU) patients in our hospital to promote more rational use of VPA in the ICU. Trough concentrations of VPA determined in 57 patients during 2019 and 2020 were retrospectively analyzed. The prescribed medicines for these patients were evaluated for potential drug interactions, the procedures adopted by the nursing staff for enteral tube administration of VPA tablets were also assessed. The average trough concentration of VPA was 33.11 ± 19.14 µg/mL, and a trough concentration within the therapeutic range of 50-100 µg/mL was achieved in 22.8% of 57 patients. Of the 57 patients on VPA, 6 were found to be co-medicated with carbapenem antibiotics, which decreased blood VPA concentrations. Moreover, the incorrect enteral tube administration procedures used by the nurses resulted in significant drug loss. After education and training of the medical staff by clinical pharmacists, these two main adverse factors were obviated. Furthermore, the hospital Pharmaceutical Management Committee adopted the recommendations and introduced VPA injection as a dosage form. After the intervention, data from a total of 88 patients on VPA in the ICU ward were collected from April 2021 to October 2024. The average VPA trough concentration in these patients was 67.69 ± 21.70 µg/mL, which was significantly higher than that before the intervention. The percentage of patients achieving a blood VPA concentration of 50-100 µg/mL increased to 80.7%, the rate of seizure control rose from 22.2% before the intervention to 65.4% after the intervention, the use of VPA injection was favored in severely ill patients to reduce the use of gavage administration. In conclusion, clinical pharmacists promoted the rational use of VPA in the ICU ward, leading to a significant increase in the average trough concentration of VPA.