Molecular Pharmacology of Topiramate: Managing Seizures and Preventing Migraine

Topiramate is a neuromodulatory compound with stabilizing properties that was initially introduced for the management of partial seizures. Topiramate has been demonstrated to modify several receptor-gated and voltage-sensitive ion channels, including voltage-activated Na⁺ and Ca²⁺ channels and non-NMDA receptors. These receptors have been implicated in the pathophysiology of both epilepsy and migraine. The pharmacological mechanisms of action for topiramate that may explain its antiepileptic and migraine preventive activities will be discussed in this review. In addition, the potential relationship between the molecular activities of topiramate and its efficacy in epilepsy and migraine prevention will be emphasized.     

Use of topiramate, a new anti-epileptic as a mood stabilizer

Rationale: Because some anti-epileptic drugs (AEDs) are effective in bipolar affective disorders, the new AED topiramate (TPM) may be effective in psychiatric illnesses. TPM was evaluated in mood disorders refractory to previous therapies including newer AEDs. Methods: Charts of 58 consecutive patients, 39 outpatients (15 males, 24 females) and 19 inpatients (6 males, 13 females) were reviewed. TPM 25 mg. b.i.d. was added to existing therapy and titrated in 50 mg increments every 3–7 days. Improvement was rated on a Likert global assessment scale of marked, moderate, mild, or no improvement or worse, based on quality of sleep, appetite, mood, and concentration. Results: Of the 58 patients with psychiatric disorders, 44 patients had rapid cycling bipolar disorders characterized by manic, hypomanic, or mixed episodes. Eighteen patients had previously failed to respond to lamotrigine and/or gabapentin in addition to conventional mood stabilizers. Fourteen were Bipolar I, six Bipolar II, and seven mixed, ten patients had cyclothymic disorder, seven had bipolar disorder not otherwise specified. Of the remaining 14 patients, nine had schizoaffective disorder, three patients had dementia and two had psychosis. Mean duration of TPM treatment was 16.0 weeks; mean TPM dosage approximately 200 mg/day. Thirty-six of 58 (62%) patients exhibited marked or moderate improvement, usually within days or weeks. Twenty-three of 44 (52%) patients with bipolar affective disorders showed marked or moderate improvement. Minimal/no improvement was observed in 16; six were rated as worse. Adverse events included delirium in one patient with Bipolar Disorder Type I who overmedicated with TPM (800 mg) and tranylcypromine sulfate (170 mg) combined with alcohol. Other adverse effects were minor and included: paresthesias, somnolence, fatigue, impaired concentration and memory, nausea, and diarrhoea. Limitations: This study was performed in a nonrandom open and retrospective fashion. Therefore, any findings are limited by the design of this study. Conclusion: TPM may be useful in patients with mood disorders unresponsive to traditional therapy and warrants further clinical investigation.     

卡马西平和托吡酯联合治疗复杂部分性癫痫29例

目的观察卡马西平和托吡酯联合治疗复杂部分性癫痫的临床疗效及安全性.方法对29例患儿在单用卡马西平治疗的基础上,加用托吡酯联合治疗.结果加用托吡酯后疗效明显,总有效率达69%,发作完全控制率占38%.结论研究结果表明,两药联合治疗复杂部分性癫痫是安全有效的.     

联用托吡酯治疗难治性癫痫临床观察

目的:观察联用托吡酯(TPM)治疗难治性癫痫(IE)的疗效与安全性.方法:采用开放性试验的方法,对20例IE患者进行治疗,以加用TPM前3个月的月均发作频率为基数,并与加用TPM后3个月的稳定期月均发作频率进行比较,同时观察其不良反应.结果:联用TPM治疗IE,总有效率达到75.0%,显效率为55.0%,其中3例(15.0%)完全控制;不良反应发生率为30.0%,为一过性,主要涉及中枢神经系统,其中2例出现体重减轻.结论:联用TPM对IE有良好疗效,安全性好.     

基于药性组合模式的托吡酯新功能发现及其作用机制研究

目的：根据药性组合模式,研究托吡酯的新功能,将中药药性理论用于老药新用途的发现。方法：根据《中药新家族——化学中药》找出托吡酯的药性,再根据糖尿病、高血压、癫痫、肺癌4种疾病的治则治法,依据功效与药性组合关系及总结其对应的药性组合模式将托吡酯的药性组合与各疾病所对应的药性组合进行比较,预测托吡酯的新功能。结果：经过比较,发现所对应的药性组合与托吡酯的药性组合相符,并有相应文献佐证,而其他几种则没有。结论：该文基于药性组合模式,通过中医临床经验,进行托吡酯新功能的筛选,发现托吡酯除对癫痫有治疗作用外,对糖尿病、高血压、肺癌亦有作用,根据药性组合模式探究药物新功能,可大大缩短新药研发的时间。     

Inhibitory effect of topiramate on Lewis lung carcinoma metastasis and its relation with AQP1 water channel

AIM: To study the effect of topiramate on tumor metastasis and its relation with aquaporin 1 (AQP1) water channel. METHODS: Lewis lung carcinoma metastatic model was used to determine the effect of topiramate on tumor growth and metastasis. Colorimetric estimation was used to investigate the action of topiramate on carbonic anhydrase (CA) activity. Western blotting and immunohistochemical analysis were used to study the influence of topiramate on AQP1 water channel expression in lungs or tumor tissues of mice bearing Lewis lung carcinoma.     

托吡酯的合成研究进展

目的 介绍托吡酯的研究背景和合成研究进展。方法 综合国内外报道的文献,阐述托吡酯的合成方法。结果 重点列出了关键中间体的合成方法以及酯化法、氨解法、催化氢化法和水解法4种托吡酯的合成方法,分析各方法。结论 氨解法是托吡酯合成方法的主要研究方向。     

托吡酯对戊四氮点燃慢性癫(癎)大鼠海马神经细胞黏附分子的影响

目的:探讨神经元活化在癫发生、发展中的作用及托吡酯对其的影响。方法:采用戊四氮制备慢性癫模型,利用托吡酯干扰,选取不同时间点,观察大鼠行为学变化及神经细胞黏附分子在海马回的表达(免疫组织化学染色)。结果:托吡酯组点燃率在27d明显低于模型组;模型组及托吡酯组神经细胞黏附分子表达增加,并随时间延长明显;而不同时间点该表达的增加程度,托吡酯组均低于模型组。结论:神经细胞黏附分子表达的增加,说明出现了神经元活化及脑可塑性变化,而托吡酯明显地抑制了该表达的增加。     

托吡酯对沙土鼠脑缺血再灌注损伤保护作用的研究

目的　探讨托吡酯对脑缺血再灌注所致脑损伤的保护作用及机制。方法　取沙土鼠 4 0只 ,随机分为 :⑴假手术组 ;⑵脑缺血再灌注组 ;⑶缺血再灌注 +托吡酯 5 0mg·kg-1组 ;⑷缺血再灌注 +托吡酯 10 0mg·kg-1组。采用短暂夹闭双侧颈总动脉法复制沙土鼠脑缺血再灌注模型 ,术后 2 4h取脑组织测定SOD、MDA、NO的改变 ,以及含水量的变化。结果　托吡酯 5 0mg·kg-1、托吡酯 10 0mg·kg-1脑组织中SOD活力明显增高、MDA、NO含量明显减少、脑组织含水量明显降低 ,与缺血再灌注组比较均有显著性差异 (P <0 0 1)。结论　托吡酯能使脑缺血再灌注损伤后脑组织中自由基的含量明显减少 ,能明显减轻脑组织水肿 ,对脑缺血再灌注损伤有保护作用。