丙戊酸群体药动学模型的建立与临床应用

目的建立门诊癫痫患者应用丙戊酸的群体药代动力学模型,并进行血药浓度预测。方法162例门诊癫痫患者连续服用丙戊酸钠达稳态,测定其谷浓度附近血样标本共196个。用非线性混合效应模型（NONMEM）考察固定效应对丙戊酸相对清除率的影响。结果体重、丙戊酸钠日剂量、合并用药等因素与清除率CL（L/h）之间的拟合模型为CL=0.00482×WT＋0.110×TAMT＋0.394×CBZS＋0.108×PHT＋0.0822×PB＋0.0583。将11例患者血药浓度预测值与实测值作线性回归,其方程为DV=1.0632×PRED—3.2665（μg/ml）,r=0.     

衍生化-高效液相色谱法测定丙戊酸血清浓度

目的 建立测定丙戊酸血清浓度的高效液相色谱法.方法 以环己羧酸为内标,血样经乙醚提取后,用氢氧化钠乙腈溶液为催化剂,经α-溴苯乙酮衍生化后用的高效液相色谱法进行测定.Shim-pack CLC-C18柱(150 mm×4.6 mm,5 μm)为色谱柱,流动相为甲醇-乙醇-四氢呋喃-水(57:10:8:25),流速为1.1 mL/min,柱温35℃,紫外检测波长为248 nm.结果 血清中丙戊酸质量浓度在10.0～200.7 μg/mL范围内与峰面积呈良好线性关系(r=0.999 8),方法回收率为99.2%～103.4%,日内与日间RSD≤5.1%.结论 该法简便、准确、专属性强,适用于临床常规监测需要.     

柱前衍生化-HPLC法测定患儿血清中丙戊酸浓度

目的:建立HPLC法测定患儿丙戊酸血清浓度的方法。方法:环己基丙酸为内标,血样经乙醚提取后,以氢氧化钠,乙腈溶液为催化剂,用α-溴苯乙酮进行衍生化。衍生物用Shim-pack CLC-C₁₈柱进行分离,流动相:甲醇-乙醇-水（65:11:24）,流速1.1 ml·min^-1。柱温为35℃,紫外检测波长为248 nm。结果:血清中丙戊酸在5.0～200.7μg·ml^-1浓度范围内呈良好线性关系（r=0.999 9）,方法回收率为104.7%～105.6%,日内与日间RSD≤5.41%。应用本方法测定32名癫痫患儿的丙戊酸血清谷浓度,16例在治疗窗(50～100μg·ml^-1)范围内,其余多数低于50μg·ml^-1。结论:本法简便、准确、专属性强,适用于临床常规监测。癫痫患儿服用丙戊酸个体差异大,应定期监测其血药浓度。     

Renal Clearance of Fluoride in a Steady State Condition in Man: Influence of Urinary Flow and pH Changes by Diet

Abstract: In order to study fluoride renal clearance, four subjects were given 3 mg fluoride as sodium fluoride tablets every 6 hrs for 60 hrs during two separate periods – during production of acid urine induced by a protein rich diet and during production of alkaline urine obtained by giving a vegetarian diet. Plasma and urine were collected every third hour for 72 hours during each experiment. In the protein rich diet period urinary pH was significantly lower than when the subjects were maintained on the vegetarian diet. Lower urinary output of fluoride during the protein rich diet experiment was recorded, however, the difference was not significant. Plasma fluoride at steady state was almost the same during both experiments. Renal fluoride clearance was significantly correlated to urinary pH in both types of experiments. When renal fluoride clearance was plotted versus urinary flow, the correlation was only significant during alkaline conditions. The average renal clearance was not significantly different between the two sets of experiments. It may be concluded, that pH and diuresis both influences fluoride renal clearance. Moreover, the results suggests that dietary components as such, influence renal clearance of fluoride in some way or another.     

高效毛细管电泳法测定丙戊酸片中主药的含量

目的:建立以高效毛细管电泳法测定丙戊酸片中主药含量的方法。方法:缓冲液为20mmol/L磷酸二氢钾10ml中加入0.01%四丁基氢氧化铵100μl,分离电压为15kV,温度为25℃,测定波长为214nm,压力进样时间为6s。结果:丙戊酸检测浓度在50～800μg/ml范围内与峰面积积分值呈良好的线性关系(r=0.9992),平均回收率为99.7%(RSD=0.68%)。结论:本方法操作简便、快速,进样量少,成本低,结果准确,可用于丙戊酸片的质量控制。     

快速柱前衍生-高效液相色谱法测定丙戊酸血药浓度

目的建立一种简便可行的快速柱前衍生-高效液相色谱法(HPLC)测定丙戊酸血药浓度。方法患者血清经正己烷提取后在C18柱上分析,流动相为甲醇-水(75∶25),柱温30℃,检测波长254 nm,流速1 mL.m in-1。结果丙戊酸在12.5~400μg.mL-1范围内线性关系良好,日内和日间RSD均小于10%(n=5)。结论本法简便、稳定,用于丙戊酸的血药浓度监测,效果良好。     

Assessment of Valproic Acid Serum–Cerebrospinal Fluid Transport by Microdialysis

The systemic disposition and serum–cerebrospinal fluid (CSF) translocation of valproic acid (VPA) were examined in rats after administration of VPA as a bolus, as a continuous infusion, or with probenecid. VPA in CSF was monitored continuously by in vivo microdialysis. Both prolonged VPA infusion and probenecid pre-treatment increased the K _m for saturable VPA elimination and decreased intrinsic hepatic clearance, perhaps due to competition of probenecid or accumulated VPA metabolites for glucuronidation or depletion of hepatic UDP-glucuronic acid. The CSF/serum VPA ratio increased rapidly initially, then decreased with time throughout the remainder of the experiment in all three groups. This time- and/ or concentration-dependent behavior suggested that the rate of CSF penetration increased disproportionately with increasing serum VPA and could be described by a kinetic model incorporating a concentration-dependent first-order rate constant for VPA influx into CSF. Under all experimental conditions, the VPA efflux from CSF appeared to be saturable; an increase in the Michaelis constant for efflux was observed following probenecid pretreatment and during VPA infusion, suggesting competitive inhibition of transport by probenecid and derived metabolites of VPA, respectively. The mechanisms responsible for asymmetric VPA transport between serum and CSF, in particular the apparent concentration-dependent change in the rate constant governing CSF penetration, remain to be elucidated.     

优化柱前衍生-HPLC法测定血清中丙戊酸的血药浓度

目的：优化柱前衍生-高效液相色谱法监测血清中丙戊酸浓度的方法。方法：以乙腈为蛋白沉淀剂,以弘溴苯乙酮为衍生化试剂进行测定。色谱柱为ANAX丙戊酸专用分析柱,流动相为乙腈-水（70：30）,柱温为40℃,流速为0．7mL·min-1,检测波长为266nm。结果：丙戊酸血药浓度在4．88-139．46μg·mL-1范围内线性关系良好（r=0．9996）,平均回收率为100．01％,日内、日间RSD均〈3％。结论：本法可简便、快速、稳定地测定血清中丙戊酸的浓度,能满足临床监测的要求。     

233例丙戊酸血药浓度监测结果分析

摘 要 目的：分析丙戊酸血药浓度监测结果,为癫痫患者丙戊酸的临床合理应用提供参考。方法: 采用回顾性研究方法,对本院确诊为癫痫的门诊和住院患者233例次的丙戊酸血药浓度及相关信息进行统计分析。结果:儿童患者中,丙戊酸日总剂量随年龄增大而增加(P<0.05);4 ~ 14岁组丙戊酸浓度达标率显著高于成人(19 ~ 50岁)组(P<0.001);丙戊酸对儿童和成人有相似的抗癫痫疗效。儿童患者以口服液为主,成人以普通片为主,且儿童比成人血药浓度达标率高(P<0.05);与单用丙戊酸相比,合用酶诱导药卡马西平、苯巴比妥和苯妥英钠显著降低丙戊酸血药浓度达标率(P<0.001),且合用苯巴比妥时丙戊酸剂量显著降低(P<0.05)。结论:丙戊酸血药浓度与疗效和不良反应有关且个体差异很大,个体化治疗时需要进行血药浓度监测。     

Age-Dependent Intestinal Absorption of Valproic Acid in the Rat

The absorption of valproic acid (VPA) across isolated perfused segments of jejunum, ileum and colon was examined in situ in 14-day-to 24-month-old Fischer-344 rats. Within each age group, the intrinsic absorptive clearance (C1_a) of VPA at a perfusate concentration of 1 mg/ml was highest in the jejunum, lowest in the colon, and intermediate in the ileum. When intestinal Cl_a was normalized for the dry weight of the segment, within-group variability decreased. In all segments, VPA Cl_a normalized by dry weight decreased during development (20 to 90 days) and remained relatively constant during aging (90 days to 24 months). The mechanism of valproate absorption (active vs. passive) was examined across age in everted intestinal sacs prepared from each of the three segments. Data were consistent with active transport of VPA in the jejunum and ileum of rats of all ages, and in the colon of pre-weanling animals. Colonic absorption of VPA appeared to occur by passive diffusion in adult rats. In contrast, colonic absorption of d-glucose occurred only by passive diffusion in all age groups. These data indicate that, during development, significant alterations in the rate of VPA absorption occur throughout the rat intestine. Furthermore, while active transport of VPA by the small intestine was present throughout the age range investigated, active transport by the colon became negligible by the time of weaning.     

酶放大免疫测定法监测丙戊酸血药浓度的结果分析

目的：通过对癫痫患者的342例次丙戊酸血药浓度监测结果分析,为临床合理用药提供参考。方法：采用酶放大免疫法检测丙戊酸血药浓度,对173例患者的342例次血药浓度进行分析,并观察其临床疗效和不良反应。结果：在342例次癫痫患者丙戊酸血药浓度监测结果中,测定值在50～100μg/ml的有150例次（占43．86％）,〈50μg/ml的有159例次（占46．49％）,〉100μg/ml的有33例次（占9．65％）。结论：丙戊酸治疗癫痫的临床疗效及不良反应与血药浓度密切相关,对丙戊酸血药浓度进行监测的结果是指导临床用药的重要依据之一,临床治疗过程中加强丙戊酸的血药浓度监测是保证疗效和安全的重要措施。     

噁丙嗪胶囊剂人体药动学及生物利用度研究

目的:探讨噁丙嗪胶囊剂人体药代动力学特征和相对生物利用度。方法:采用随机交叉法单次给予8名受试者噁丙嗪胶囊剂或片剂600mg后,于不同时间取血浆样本,高效液相色谱法测定受试者血浆中药物浓度,运用TopFit药动学软件的非房室模型拟合药时曲线,计算药代动力学参数及相对生物利用度。结果:统计学分析显示,两制剂的t_(1/2)、MRT、Cl和AUC_(0～∞)均无显著性差异(P>0.05)。药一时曲线呈双峰现象,可能与药物的肠肝循环有关。两制剂的达峰浓度Cp_1及Cp_2均差异显著(P<0.05)。结论:胶囊剂相对于片剂的生物利用度为121.06％,胶囊剂的吸收程度优于片剂,有利于临床治疗应用。     

Neuroprotection by Valproic Acid in Mouse Models of Permanent and Transient Focal Cerebral Ischemia

Valproic acid (VPA) is a well-known anti-epileptic and mood stabilizing drug. A growing number of reports demonstrate that VPA is neuroprotective against various insults. Despite intensive efforts to develop new therapeutics for stroke over the past two decades, all treatments have thus far failed to show clinical effect because of treatment-limiting side effects of the drugs. Therefore, a safety-validated drug like VPA would be an attractive candidate if it has neuroprotective effects against ischemic insults. The present study was undertaken to examine whether pre- and post-insult treatments with VPA protect against brain infarct and neurological deficits in mouse transient (tMCAO) and permanent middle cerebral artery occlusion (pMCAO) models. In the tMCAO (2 hr MCAO and 22 hr reperfusion) model, intraperitoneal injection of VPA (300 mg/kg, i.p.) 30 min prior to MCAO significantly reduced the infarct size and the neurological deficit. VPA treatment immediately after reperfusion significantly reduced the infarct size. The administration of VPA at 4 hr after reperfusion failed to reduce the infarct size and the neurological deficit. In the pMCAO model, treatment with VPA (300 mg/kg, i.p.) 30 min prior to MCAO significantly attenuated the infarct size, but did not affect the neurological deficit. Western blot analysis of acetylated H3 and H4 protein levels in extracts from the ischemic cortical area showed that treatment with VPA increased the expression of acetylated H3 and H4 at 2 hrs after MCAO. These results demonstrated that treatment with VPA prior to ischemia attenuated ischemic brain damage in both mice tMCAO and pMCAO models and treatment with VPA immediately after reperfusion reduced the infarct area in the tMCAO model. VPA could therefore be evaluated for clinical use in stroke patients.     

Structure Activity Relationship of Human Microsomal Epoxide Hydrolase Inhibition by Amide and Acid Analogues of Valproic Acid

Purpose. The purpose of this study was to evaluate the in vitro inhibitory potency of various amide analogues and derivatives of valproicacid toward human microsomal epoxide hydrolase (mEH). Methods. mEH inhibition was evaluated in human liver microsomeswith 25 (S)-(+)-styrene oxide as the substrate. Inhibitory potencyexpressed as the median inhibitory concentration (IC₅₀) was calculatedfrom the formation rate of the enzymatic product,(S)-(+)-1-phenyl-1,2-ethanediol. Results. Inhibitory potency was directly correlated with lipophilicityand became significant for amides with a minimum of eight carbonatoms. Branched eight-carbon amides were more potent inhibitors thantheir straight chain isomer, octanamide. N-substituted valproylamideanalogues had reduced or abolished inhibition potency with theexception of valproyl hydroxamic acid being a potent inhibitor. Inhibitionpotency was not stereoselective in two cases of chiral valpromideisomers. Valproyl glycinamide, a new antiepileptic drug currentlyundergoing phase II clinical trials and its major metabolite valproylglycine were weak mEH inhibitors. Acid isomers of valproic acid werenot potent mEH inhibitors. Conclusions. The structural requirements for valproylamide analoguesfor potent in vitro mEH inhibition are: an unsubstituted amide moiety;two saturated alkyl side chains; a minimum of eight carbons in themolecule.     

HPLC-MS／ESI测定人血清中丙戊酸浓度

目的:建立HPLC-MS／ESI测定人血清中丙戊酸浓度的方法,并用于临床血药浓度监测。方法:采用Waters XTerraTM MS C18色谱柱(150 mm×3．9 mm,5μm),以10 mmol·L-1醋酸铵水溶液-乙腈(60:40)为流动相,流速0．80 mL·min-1,柱温45℃,以双氯芬酸为内标。采用电喷雾电离源(ESI)负源,用各物质准分子离子峰的选择离子监测(SIR)进行定量分析,血清样品用乙腈直接沉淀后进样。结果:丙戊酸在7．25-188．10μg·mL-1浓度范围内线性关系良好(r=0．9997),最低检测浓度为0．50μg·mL-1(S／N≥3)。日内与日间RSD均小于10％(n=5),方法回收率在98．7％-105．1％之间。结论:该方法操作简单,结果准确,血药浓度监测时间很短,灵敏度高;适用于丙戊酸血药浓度监测及药代动力学研究。     

GC测定丙戊酸钠缓释片的有关物质

目的 建立毛细管气相色谱法检测丙戊酸钠缓释片有关物质的方法。方法 采用聚乙二醇为固定液的HP-FFAP色谱柱（30 m×0.53 mm,1 μm）,柱温为程序升温;氮气为载气,流速为10 mL·min^-1;直接进样1.0 μL,进样口温度200℃;采用氢火焰离子化检测器,检测器温度250℃。结果 建立的方法专属性强,能有效分离丙戊酸钠缓释片中的10个杂质;丙戊酸在1.01~8.06 μg·mL^-1内线性关系良好（r=0.998 2,n=5）,最低检出限为0.403 μg·mL^-1。方法重复性良好,各杂质加样回收率均>90%,且RSD均<5%。结论 该方法可用于丙戊酸钠缓释片的有关物质检测。     

丙戊酸治疗躁狂症及其血药浓度的临床对照研究

目的探讨丙戊酸治疗躁狂症的临床疗效、血药浓度及药物不良反应。方法60例躁狂症患者分别接受丙戊酸钠缓释剂及丙戊酸镁治疗6周,并于服药后1,2,4,6周末使用高效液相色谱法检测丙戊酸血药浓度,以Bech—Rafaelsen躁狂量表（BRMS）和不良反应量表（TESS）观察临床疗效和药物不良反应。结果观察组有效率为80．00％,对照组有效率为76．67％,两组疗效无明显差异,有效病例的血药浓度平均为（77．58±14．45）μg·mL^-1,治疗窗范围为50～100μg·mL^-1之间。结论丙戊酸能有效治疗躁狂症,血药浓度监测有助于临床安全有效用药。     

我院丙戊酸钠血药浓度监测结果分析

目的:分析我院丙戊酸钠血药浓度监测结果,探讨影响儿童丙戊酸钠血药浓度的因素,为临床合理用药提供参考。方法:采用均相酶放大免疫法对我院门诊及病区服用丙戊酸钠的癫痫患儿进行血药浓度监测,对监测结果进行统计分析。结果:进行血药浓度监测的1 671例患儿中,871例(52.12%)血药浓度为50~100 μg/mL,10例(0.60%)血药浓度为0 μg/mL,719例(43.03%)血药浓度<50 μg/mL,71例(4.25%)血药浓度>100 μg/mL。患儿性别与年龄对丙戊酸钠有效血药浓度比率无明显影响(P>0.05),用药依从性及合并用药对丙戊酸钠有效血药浓度比率有影响(P<0.05)。结论:应重视和加强丙戊酸钠血药浓度监测并实施个体化给药,保障患儿用药安全。     

HPLC法测定丙戊酸血清浓度的衍生化条件考察

目的：考察丙戊酸的衍生化条件,并建立测定丙戊酸血清浓度的方法。方法：血样采用α-溴苯乙酮衍生化,用高效液相色谱（HPLC）法进行测定。以丙戊酸衍生物产率为指标,采用单因素法考察反应温度、时间、三乙胺用量、衍生化试剂用量对丙戊酸衍生化的影响。结果：丙戊酸完全衍生化的条件为衍生化试剂用量400-600μg、三乙胺用量10～20μL、在45-60℃条件下反应20-60min。丙戊酸血药浓度在5．0-200．7μg·mL-1范围内线性关系良好（r=0．9999）,方法回收率为99．80％～100．43％,日内与日间RSD≤4．45％。结论：衍生化试剂用量、三乙胺用量、反应温度和时间等对丙戊酸衍生化产率有较大的影响,在丙戊酸血清浓度测定中应加以控制。