Quantification of carbamazepine, carbamazepine-10,11-epoxide, phenytoin and phenobarbital in plasma samples by stir bar-sorptive extraction and liquid chromatography

A sensitive and reproducible stir bar-sorptive extraction and high-performance liquid chromatography-UV detection (SBSE/HPLC-UV) method for therapeutic drug monitoring of carbamazepine, carbamazepine-10,11-epoxide, phenytoin and phenobarbital in plasma samples is described and compared with a liquid:liquid extraction (LLE/HPLC-UV) method. Important factors in the optimization of SBSE efficiency such as pH, extraction time and desorption conditions (solvents, mode magnetic stir, mode ultrasonic stir, time and number of steps) assured recoveries ranging from 72 to 86%, except for phenytoin (62%). Separation was obtained using a reverse phase C(18) column with UV detection (210nm). The mobile phase consisted of water:acetonitrile (78:22, v/v). The SBSE/HPLC-UV method was linear over a working range of 0.08-40.0mugmL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125-40.0mugmL(-1) for phenytoin, The intra-assay and inter-assay precision and accuracy were studied at three concentrations (1.0, 4.0 and 20.0mugmL(-1)). The intra-assay coefficients of variation (CVs) for all compounds were less than 8.8% and all inter-CVs were less than 10%. Limits of quantification were 0.08mugmL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125mugmL(-1) for phenytoin. No interference of the drugs normally associated with antiepileptic drugs was observed. Based on figures of merit results, the SBSE/HPLC-UV proved adequate for antiepileptic drugs analyses from therapeutic levels. This method was successfully applied to the analysis of real samples and was as effective as the LLE/HPLC-UV method.     

HPLC法测定去痛片中4种成分的含量

目的：建立HPLC法同时测定去痛片中4种组分的方法。方法色谱柱为Kromasil C18（100×4．6mm,3．5μm）;柱温30℃;以0．05mol?L－1磷酸二氢钾溶液（pH为7．0±0．1）∶甲醇（55∶45）为流动相;流速为0．7mL?min－1;检测波长为220nm。结果4种组分可完全分离,线性关系良好,咖啡因、苯巴比妥、氨基比林、非那西丁的加样回收率分别为：98．68％、98．21％、101．99％、99．80％,RSD均小于1．2％。结论本方法操作简单,结果准确可靠,可以有效地用于控制去痛片的药品质量。     

Stereological examination of curcumin’s effects on hippocampal damage caused by the anti-epileptic drugs phenobarbital and valproic acid in the developing rat brain

The anti-epileptic drugs phenobarbital and valproic acid have an extremely strong negative effect on cognitive processes such as learning and memory in the developing brain. We examined whether or not curcumin has protective effects on neuronal injury caused by these drugs in the developing rat brain. Young male Wistar rats were studied in two groups, a 7 days old and a 14 days old group (35 rats in each). Both groups were then divided into 7 sub-groups as the control, curcumin, dimethylsulfoxide, phenobarbital, valproic acid, phenobarbital + curcumin, and valproic acid + curcumin groups (n = 5 in each group). At 24 h after the intraperitoneal injection of the compounds, the rats were sacrificed, and the hippocampal tissue was subjected to stereological analysis with the optical fractionation method. Total numbers of neurons in the hippocampus of the 7 days old and 14 days old rats were calculated. It was found that treatment with phenobarbital resulted in a loss of 43% of the neurons, and valproic acid induced a loss of 57% of the neurons in the 7 days old rats. Curcumin prevented this loss significantly with only 19% in the phenobarbital group and 41% in the valproic acid group. In the 14 days old rat groups, phenobarbital was found to reduce the number of neurons by 30%, and valproic acid reduced it by 38%. Curcumin treatment limited neuronal loss to 3% in the phenobarbital + curcumin group and 10% in the valproic acid + curcumin group. These data strongly indicate that curcumin is a protective agent and prevents hippocampal neuronal damage induced by phenobarbital and valproic acid treatment.     

静注负荷量苯巴比妥治疗新生儿惊厥(附100例临床分析)

对100例新生儿惊厥采用负荷量苯巴比妥静注治疗,在病因治疗的基础上,苯巴比妥一般按20～30mg／kg,最高达35mg／kg,短时间内静脉给药,12小时后给予维持量。总有效率为94％。疗效出现时间最短3分钟,最长55分钟。临床观察结果表明该疗法对新生儿惊厥不仅起效快,疗效明显,而且到作用小,使用安全可靠,是治疗新生儿惊厥的首选方法。     

苯巴比妥联合地西泮治疗急诊小儿惊厥的效果观察

目的 观察苯巴比妥联合地西泮治疗急诊小儿惊厥的临床效果.方法 94例惊厥患儿,采用随机数字表法分为对照组和研究组,各47例.对照组给予地西泮治疗,研究组给予苯巴比妥联合地西泮治疗.比较两组患儿临床疗效、惊厥症状控制时间、实验室相关指标及复发率.结果 研究组总有效率95.74％高于对照组的72.34％,差异有统计学意义(...     

160例中国农村地区癫痫防治管理示范项目患者退组原因及依从性分析

[目的]了解农村地区癫痫患者服用苯巴比妥单药治疗的依从性和退组原因。[方法]对绵阳市游仙区、三台县农村地区惊厥型癫痫患者服用苯巴比妥,观察退组时间、退组原因及依从性,并对其数据进行统计分析。[结果]观察患者555例,其中160例患者在不同时期退组;退组人数在前3个月数量较大,第4月开始趋于平稳,第7月后开始显著减少;其退组主要原因有疗效差、失访、拒绝服药等;退组患者服药的依从性明显不及未退组患者。[结论]农村地区癫痫患者服用苯巴比妥治疗癫痫的前3个月易退组,且退组的患者依从性明显低于未退组患者,故需在服药初期加强对患者依从性教育及癫痫知识的普及以减少退组的发生。     

血药浓度监测在儿童癫痫规范化治疗中的临床意义研究

目的探讨血药浓度监测在儿童癫痫规范化治疗中的临床意义。方法采用高效液相色谱法对我院192例癫痫惠儿使用丙戊酸钠或苯巴比妥后的血药浓度进行了576次监测,对监测结果进行分析与评价。结果服用丙戊酸钠患儿456例次．其血药浓度达到有效范围的占51.97％,服用苯巴比妥患儿120例次,其血药浓度达到有效范围的占45．0％。结论血药浓度监测对于规范化治疗儿童癫痫临床用药的科学合理化、安全有效性有重要价值。     

Bone and calcium metabolism and antiepileptic drugs

There is increasing evidence suggesting that epilepsy and its treatment can affect bone mineralization and calcium metabolism. Many studies have shown a significant reduction in bone mineral density in patients treated with classic (phenobarbital, carbamazepine, valproate, etc.) and with new (oxcarbazepine, gabapentin) antiepileptic drugs. In spite of data about the possible effects of the antiepileptic drugs on calcium metabolism, the mechanisms of this important side effect remain to be defined. The abnormalities of calcium metabolism were thought to result from the cytochrome P450 enzyme-inducing properties of some antiepileptic drugs and the resultant reduction in vitamin D levels, but the effect of many medications (e.g., valproate) cannot be readily explained by vitamin D metabolism.     

High seizure frequency prior to antiepileptic treatment is a predictor of pharmacoresistant epilepsy in a rat model of temporal lobe epilepsy

Purpose:   Progress in the management of patients with medically intractable epilepsy is impeded because we do not fully understand why pharmacoresistance happens and how it can be predicted. The presence of multiple seizures prior to medical treatment has been suggested as a potential predictor of poor outcome. In the present study, we used an animal model of temporal lobe epilepsy to investigate whether pharmacoresistant rats differ in seizure frequency from pharmacoresponsive animals.
Methods:   Epilepsy with spontaneous recurrent seizures (SRS) was induced by status epilepticus. Frequency of SRS was determined by video/EEG (electroencephalography) monitoring in a total of 33 epileptic rats before onset of treatment with phenobarbital (PB).
Results:   Thirteen (39%) rats did not respond to treatment with PB. Before treatment with PB, average seizure frequency in PB nonresponders was significantly higher than seizure frequency in responders, which, however, was due to six nonresponders that exhibited > 3 seizures per day. Such high seizure frequency was not observed in responders, demonstrating that high seizure frequency predicts pharmacoresistance in this model, but does not occur in all nonresponders.
Discussion:   The data from this study are in line with clinical experience that the frequency of seizures in the early phase of epilepsy is a dominant risk factor that predicts refractoriness. However, resistance to treatment also occurred in rats that did not differ in seizure frequency from responders, indicating that disease severity alone is not sufficient to explain antiepileptic drug (AED) resistance. These data provide further evidence that epilepsy models are useful in the search for predictors and mechanisms of pharmacoresistance.     

琥珀酸对惊厥幼鼠小脑浦肯野细胞的保护作用

目的 探讨琥珀酸(SA)对惊厥幼鼠小脑浦肯野细胞(PC)的保护作用。方法 将健康新生7 d Sprague-Dawley(SD)幼鼠120 只随机分为新生期组和发育期组,两组再随机分为正常对照组、惊厥模型组、小剂量苯巴比妥(PB)组(30 mg/kg)、大剂量PB 组(120 mg/kg)、小剂量琥珀酸(SA)组(30 mg/kg)、大剂量SA 组(120 mg/kg)。利用腹腔注射戊四氮制备幼鼠惊厥模型,正常对照组应用生理盐水替代。新生期各组大鼠分别在注射PB 或SA 或生理盐水后30 min 处死取小脑,发育期各组大鼠分别在注射PB 或SA 或生理盐水后养至30 d 时处死取小脑。采用全细胞膜片钳技术,在各组幼鼠小脑脑片上记录PC 动作电位(AP);采用低频刺激平行纤维(PF)诱发兴奋性突触后电流(EPSC),观察SA 对各组大鼠PC 长时程抑制(LTD)的影响。结果 与对照组相比,新生期和发育期惊厥幼鼠PC AP 频率均明显增高(P<0.05),发育期惊厥幼鼠PC AP 阈刺激明显降低(P<0.01),且PC EPSC 的幅值抑制程度明显增强(P<0.05);与对照组相比,新生期和发育期大剂量PB 组惊厥幼鼠PC AP 阈刺激明显降低(P<0.01),PC AP 频率明显增高(P<0.05),PC EPSC 抑制程度明显增强(P<0.05);新生期和发育期大剂量SA 组惊厥幼鼠PC AP 频率与惊厥组相比均明显降低(P<0.05);发育期两种剂量SA 组AP 产生的阈值与惊厥组相比均明显增高(P<0.05)。结论 SD 幼鼠新生期惊厥导致的小脑PC 兴奋性增高和PF-PC 突触可塑性异常可持续至发育期,PB 可能加重这种异常,而SA 能降低惊厥幼鼠小脑PC 的兴奋性,并对惊厥造成的PC LTD 的近期和远期异常有明显的修复作用。