英文药名：Fostoin（Fosphenytoin Sodium Hydrate for Injection）

中文药名：磷苯妥英钠水合物

生产厂家：卫材有限
药品介绍
商標名
Fostoin 750mg for Injection
一般名：
ホスフェニトインナトリウム水和物
（Fosphenytoin Sodium Hydrate）
化学名：
Disodium（2,5-dioxo-4, 4-diphenylimidazolidin-1-yl）methyl phosphate heptahydrate
分子式：
C16H13N2Na2O6P・7H2O
分子量：
532.34（無水物として406.24）
構造式：

性　状：
磷苯妥英钠水合物是固体白色至淡黄色。它易溶于水，微溶于乙醇（99.5）。
药理作用
本品是在全世界第一个被批准上市的苯妥英钠前体药，具有高效抗惊厥作用。通过小鼠抗电休克试验测得本品腹腔注射或口服给药的抗惊厥作用（抗最大电休克发作）半数有效剂量ED50（mg/kg）各为10.3、11.8，苯妥英的腹腔注射或口服给药ED50（mg/kg）各为9.5、0.4，表明本品与苯妥英具有同等程度的抗惊厥作用。但是小鼠腹腔注射给红色的旋转毒性TD50(mg/kg)本品为42.1苯妥英为65.4，本品旋转毒性较苯妥英大些，这是由于本品是苯妥英的前体，容易被机体吸收所致。给大鼠腹腔注射高半胱氨酸5.5mmol/kg引起大鼠癫发作，将动物分组，每组9只大鼠，分别腹腔给本品130mg/kg和苯妥英120mg/kg，用脑电图监察给药结果。给药后30min，本品在大鼠脑内浓度几乎与苯妥英相同，60min时未测得本品血药浓度峰值，但是在给药后1~2h期间苯妥英给药组大鼠的血药浓度及脑内浓度变化较本品组显著接收本品的大鼠没有1只中止癫发作，而苯妥英组大鼠有4只中止发作，此结果差异在于本品注射后转化为苯妥英需要一定时间。
本品与苯妥英相似具有抗心律失常作用。本品为苯妥因前体药，在豚鼠动脉的体外试验中，因本品未转化为苯妥因而无抗心律失常作用，而苯妥英显示抗心律失常作用。可是在动物体内本品与苯妥英等效地拮抗哇巴因引起的心律失常。以麻醉狗进行试验评价本品对心血管作用。分别静注本品27mg/kg、苯妥英18mg/kg（两药为等分子剂量）。迅速静注苯妥英的狗立即发生及明显降低左心室压力增高率、降低平均动脉压和心率，然后反射性地加快心率。而本品仅引起较小的血流动力学变化。这与本品不引起临床上明显的心血管系统的不良反应是一致的。
适应症
本品用于控制原发性癫痫病人的痉挛症状，预防并治疗神经外科手术中惊厥的发作。
用法用量
通常情况下，两岁以上或者成人岁以下的儿童，应该给予一个剂量方案如下。
1. 癫痫持续状态
首次剂量
静脉注射22.5mg/kg作为磷苯妥英钠。剂量率不得超过150毫克/分或为3mg/kg/分钟的低。
维持剂量
予静脉内给药一次或分次5〜7.5mg/kg/天为磷苯妥英钠。剂量率不得超过75毫克/分或为1mg/kg/分钟的低。
2. 制止意识癫痫发作紊乱（头部外伤等），或者当脑外科的表达
首次剂量
静脉注射为18mg/kg〜作为磷苯妥英钠。剂量率不得超过75毫克/分或为1mg/kg/分钟的低
维持剂量
予静脉内给药一次或分次5〜7.5mg/kg/天为磷苯妥英钠。剂量率不得超过75毫克/分或为1mg/kg/分钟的低。
3. 暂时性癫痫患者苯妥英的口服替代疗法
予静脉内给药在一个划分或每日一次，每日剂量的口服苯妥英钠为磷苯妥英钠1.5倍。剂量率不得超过75毫克/分或为1mg/kg/分钟的低。
注意事项
对本品或其制剂成分、苯妥英或其他乙内酰脲药物过敏者禁用，心功能异常者禁用。紫质症病人慎用本品，因苯妥英可使其症状加重。与苯妥英有相互作用的药物也可与本品发生作用，如影响血浆蛋白结合或细胞色素P450酶系统的药物，使用时需注意。
包装
ホストイン静脉注射750毫克  2瓶
製造販売元

注：使用请参照原处方：http://www.info.pmda.go.jp/go/pack/1132401A1020_1_02/
Nobelpharma and Eisai Announce Japan Launch of Anticonvulsant Agent
Fostoin 750mg for Injection
Fostoin is a water-soluble prodrug of phenytoin injection, a drug that has long been used both in Japan and overseas as a treatment for status epilepticus and other such conditions. By providing phenytoin as a water-soluble prodrug, the agent will significantly reduce local irritation during intravenous infusion and is expected to enhance tolerability.
1. About Fostoin 750 mg for Injection
Fostoin 750 mg for Injection (fosphenytoin sodium hydrate) is a water soluble prodrug of phenytoin that has long been used both in Japan and overseas as a treatment for status epilepticus and other such conditions. It exerts its effects after undergoing rapid alkaline phosphatase(an enzyme found in the blood and organs)catalyzed hydrolyzation to yield its active metabolite phenytoin.
By providing phenytoin as a water-soluble prodrug, it is possible to significantly reduce local irritation during intravenous infusion and to enhance tolerability.
As of January 2011, Fostoin is approved in 24 countries, including the United States, the United Kingdom and France, for the control of status epilepticus and the prevention and treatment of seizures occurring during neurosurgery or head injury as well as an alternative treatment when oral administration of phenytoin is unavailable or inappropriate.
2．Product Outline
1) Product Name
Fostoin 750 mg for Injection
2) Generic Name
fosphenytoin sodium hydrate
3) Indications and Usage
1. Status epilepticus
2. Suppression of seizure onset during neurosurgery or impaired consciousness (head injury, etc.)
3. Temporary alternative therapy for epilepsy patients being administered oral phenytoin
4) Dosage and Administration
The following dosage and administration is recommended for adults and children over two years of age
1. Status epilepticus
Loading Dose
The loading dose of fosphenytoin sodium is 22.5 mg/kg administered intravenously. The dose should be administered no faster than 3mg/kg/minute or 150mg/minute, whichever in lower.
Maintenance Dose
The maintenance dose of fosphenytoin sodium is 5~7.5 mg/kg/day administered intravenously as a single dose or divided equally into several doses. The dose should be administered no faster than 1mg/kg/minute or 75mg/minute, whichever in lower.
2．Suppression of seizure onset during neurosurgery or impaired consciousness (head injury, etc.)
Loading Dose
The loading dose of fosphenytoin sodium is 15~18 mg/kg administered intravenously. The dose should be administered no faster than 1 mg/kg/minute or 75 mg/minute, whichever in lower.
Maintenance Dose
The maintenance dose of fosphenytoin sodium is 5~7.5 mg/kg/day administered intravenously as a single dose or divided equally into several doses. The dose should be administered no faster than 1mg/kg/minute or 75mg/ minute, whichever in lower.
3. Temporary alternative therapy for epilepsy patients being administered oral phenytoin
Fosphenytoin sodium should be administered intravenously once daily or divided equally into several doses at a dose equivalent to 1.5 times that of oral phenytoin. The dose should be administered no faster than 1mg/kg/minute or 75mg/minute, whichever in lower.
5) Price
Fostoin 750 mg for Injection     
6) Packaging
Fostoin 750 mg for Injection Two vials
7) Manufacturer:
Nobelpharma Co., Ltd.
8) Distributor:
Eisai Co., Ltd.
3. Eisai’s Commitment to Epilepsy
Eisai defines epilepsy as a therapeutic area of focus, currently marketing Zonegran® (under license from the originator Dainippon Sumitomo Pharma Co., Ltd.; sodium/calcium channel blocking antiepileptic agent; marketed in Europe, the United States and Asia) and Zebinix(under license from the originator BIAL-Portela & Ca S.A.; voltage-dependent sodium channel-blocking antiepileptic agent; marketed in Europe) as adjunctive therapies in adults with partial onset seizures, and Inovelon®/BANZEL® (under license from the originator Novartis AG; sodium channel-blocking novel triazole derived antiepileptic agent; marketed in Europe (Inovelon), Asia(BANZEL®), and the North America (BANZEL) for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome, a severe form of early childhood-onset epilepsy.
Marketing authorization applications seeking approval of the AMPA receptor antagonist perampanel as a novel treatment for partial-onset seizures in patients with epilepsy are currently under regulatory review in the United States and European Union (EU). The agent is also being evaluated for the same indication in phase II studies being conducted in Japan as well as in global phase III studies for generalized epilepsy. Eisai also plans to conduct further studies to investigate the potential of perampanel as a monotherapy in partial-onset seizures and for the treatment of other forms of epilepsy such as Lennox-Gastaut syndrome.
By offering multiple treatment options as part of its abundant product lineup, Eisai will continue to make further contributions to address the diversified needs of, and increase the benefits provided to, epilepsy patients and their families.
4. Glossary of Terms
1) Epilepsy
Epilepsy is chronic neurological condition that is caused by a variety of factors, and which is characterized by repetitive seizures that are triggered by overactivity of neurons in the brain.
During seizures, patients may experience both convulsive and non-convulsive symptoms such as convulsions and loss of consciousness, as well as those that are not always recognized as seizures, such as blank staring, lip smacking, or jerking movements of arms and legs.
Epilepsy can develop at any age and is thought to affect an estimated one million people in Japan.
2) Status epilepticus
Status epilepticus is defined as an unremitting seizure that continues for an extended length of time or short recurrent seizures without regaining consciousness. As status epilepticus may cause severe permanent brain damage in left untreated, the utmost priority
is given to suppressing seizures.
3) Convulsive Seizure
Convulsive　seizures occur as a result of the brain sending out abnormal signals that are triggered by damage to part of the brain.
When these abnormal signals occur in neurons associated with movement, they cause a patient’s arms and legs on the side of the body controlled by the respective neurons to contract involuntarily. Most seizures normally subside within several minutes.
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产地国家：日本
原产地英文商品名:
Fostoin（ホストイン静注）750MG/ML 10MLS/VIAL 2VIALS/BOX
原产地英文药品名:
FOSPHENYTOIN SODIUM
中文参考商品译名:
Fostoin注射剂（ホストイン静注）750毫克/毫升 10毫升/瓶 2瓶/盒
中文参考药品译名：
磷苯妥英钠
生产厂家英文名：
Eisai Co., Ltd.
生产厂家中文参考译名：
卫材