Kodama Y, Kuranari M, Kodama H, Koike Y, Yasunaga F, Fujii I, Takeyama M
Department of Clinical Pharmacy, Oita Medical University, Japan.
Int J Clin Pharmacol Ther. 1995 Feb;33(2):114-8.
We retrospectively evaluated the ability of Scatchard binding equation method to predict the unbound serum valproic acid (VPA) concentration in 37 pediatric patients with epilepsy receiving VPA monotherapy. The correlation between predicted and observed unbound serum concentrations was high and significant (r = 0.873, p < 0.001). Mean prediction error (ME), mean absolute prediction error (MAE), and root mean squared error (RMSE) were calculated, and served as a measure of prediction bias and precision. The 95% confidence intervals of ME did not include 0, showing a bias to overpredict unbound concentration. The MAE and RMSE were not small in magnitude (MAE 17.4 mumol/l, RMSE 22.8 mumol/l). The current method using the in vivo population mean binding parameters from healthy young adults may be limited in the predictive performance of unbound serum VPA concentration.
我们回顾性评估了Scatchard结合方程法预测37例接受丙戊酸（VPA）单药治疗的癫痫患儿血清中游离丙戊酸（VPA）浓度的能力。预测的和观察到的血清游离浓度之间的相关性很高且具有显著性（r = 0.873，p < 0.001）。计算了平均预测误差（ME）、平均绝对预测误差（MAE）和均方根误差（RMSE），并将其作为预测偏差和精度的度量。ME的95%置信区间不包括0，表明存在高估游离浓度的偏差。MAE和RMSE的数值不小（MAE为17.4 μmol/L，RMSE为22.8 μmol/L）。目前使用健康年轻成年人的体内群体平均结合参数的方法在预测血清游离VPA浓度的性能方面可能存在局限性。
