美国批准首种治疗末期阿兹海默症药物Namenda上市
美国卫生官员周五批准第一种治疗末期阿兹海默症（俗称老人痴呆症，Alzheimer’s Disease）的药物上市。据估计美国罹患老人痴呆症的患者达400万。
美国食品药物管理局（FDA）称，获准上市的药物是由Forest Laboratories（FRX）生产的Namenda。临床试验显示，该药有助减缓中到重度老人痴呆症患者意识、推理，以及日常生活机能的衰退速度。
FDA称，钟万剑研究显示，多数老年痴呆症患者的心理与生活机能确实有退化的情形。但平均来说，服用Namenda的患者在如独立进食、拨打电话等生活能力上的表现，要优于服用安慰剂的患者。
Forest Laboratories投资人关系副总裁特里亚诺（Charles Triano）称，Namenda应该会在明年1月上市。
FDA称，在临床试验中，Namenda被单独或与其他老人痴呆症药物一起使用，其副作用较小，包括眩晕、头痛和便秘等。
 
英文药名: Namenda (Memantine)

中文药名: 盐酸美金刚（美金刚胺）

药品简介
阿尔茨海默氏病（Alzheimer’s disease，AD），又称老年性痴呆，是一种与衰老相关，以认知功能下降为特征的渐进性脑退行性疾病或综合症。病人整个大脑弥散性萎缩并出现明显的病理组织学改变——老年斑（senile plaque, SP）（或神经炎性斑，neuritic plaque）和神经原纤维缠结(neurofibrillary tangle, NFT)。病人认知功能下降并伴有神经元功能障碍、神经元数量减少、神经元体积扩大及突触缺失（I型营养障碍轴突）和胞内磷酸化tau（microtubule-associated protein tau）形成的成对螺旋丝，即NFT（II型营养障碍轴突）。此外，胞外的淀粉样蛋白（amyloid β-protein, Aβ）沉积形成SP，其周围环绕着营养障碍的突起。Aβ沉积形式由早期的弥散型聚集（不成熟的弥散斑）到形成成熟的致密斑，后者由直径为8nm的原纤维组成，用刚果红染色后在偏振光的照射下表现出双折射的特性。晚期的病理变化是由激活的小胶质细胞和星形胶质细胞参与的炎性反应所引起的，它们包围着沉积斑块。该病早期的行为学改变为轻微的记忆紊乱或个性改变，在5~10年内逐渐恶化，最终出现严重痴呆症状，生活不能自理。这种隐袭和破坏性的大脑退行性疾病剥夺了受害者最具人类特征的品质——记忆、推理、抽象化和语言的能力。
一、临床症状
AD几乎都是以不可觉察的方式开始发病，最初常常是偶然地、在回忆日常生活最近事件时遇到困难。病人可能无法回忆与某个人的交谈或参与过的某项活动，或者可能是对最近接受的某个项目的信息变得很迷惑，亦即以轻微认知障碍 (mild cognitive impairment，MCI)为先兆。患者往往是以纯粹的遗忘症状开始，其他认知方面很少或根本没有任何困难。MCI或早期AD患者完全保持清醒状态，没有明显的语言混乱，并保持着正常的运动和感觉功能。
AD发病的最初几年，多数病人在一般认知功能方面即已出现一些问题，例如在时间感和空间感及进行正确自如的复杂操作方面屡屡出错，并出现用词和数学运算困难等。当这些轻微的差错变得逐渐引人注意时，病人可能对一些活动和爱好变得索然无趣、出现情感淡漠、情绪不稳定了。在渐进性的记忆和认知功能衰退后，许多病人开始经历第一次、然而是比较明显的运动功能障碍，包括手工操作、写作、绘画、正常行走等。在几年或十几年的病程中，AD会逐渐恶化到明显痴呆的地步。由于定向力完全丧失、记忆力严重缺损及认知功能障碍，许多病人活动受限，被迫常常坐着或躺着，最后可能死于某些小的呼吸系统疾病，如误吸或肺炎等。
二、神经递质改变
AD脑组织中发现的第一个神经递质异常是乙酰胆碱（Ach），合成和降解Ach的酶活性发生改变。因此，AD内侧隔核和基底前脑胆碱能神经元的数量与质量都发生变化。然而，在这些递质缺乏的同时，很快伴随着其他递质神经元的减少或丧失，包括谷氨酸（Glu）、γ-氨基丁酸（GABA）、生长抑素（SST）、促肾上腺皮质激素释放因子（CRF）和5-羟色胺（5-HT）等等。因此，AD神经递质缺乏是广泛性的，并且，还没有关于各种神经元亚型遭破坏过程的清晰线索。直到现在，只有胆碱能递质功能不足被真正用于AD治疗。
盐酸美金刚胺（memantine hydrochloride，，Namenda）——用于治疗中晚期阿尔茨海默氏病（老年性痴呆）
多奈哌齐和重酒石酸卡巴拉汀具有副作用少，老年病人容易耐受的优点；盐酸美金刚胺是美国FDA批准用于治疗中晚期阿尔茨海默氏病（老年性痴呆）的唯一药物，它的作用机制独特，是第一个在阿尔茨海默氏病和血管性痴呆方面有显著疗效的NMDA拮抗剂，当谷氨酸以病理量释放时，美金刚胺可减少谷氨酸的神经毒性作用，当谷氨酸释放过少时，美金刚胺可以改善记忆过程所需谷氨酸的传递，临床研究表明美金刚胺用于老年痴呆症患者具有较好的耐受性，在精神病理学和行为测定中产生温和的有统计学意义的显著改善，有研究表明美金刚胺与其它药物联合使用可以增加疗效，但在没有确切适应症批准之前，我们不推荐联合用药；神经节苷脂（Ganglioside，简称GM）是一种复合糖脂，存在于哺乳动物细胞，特别是神经元细胞的胞膜中，是神经细胞膜的天然组成部分，神经节苷脂能从各方面影响神经膜的功能，改善阿尔茨海默氏病（老年性痴呆）患者记忆力。
ＦＤＡ日前批准美金刚（Ｎａｍｅｎｄａ）治疗中重度阿尔茨海默病，这也是第一个获ＦＤＡ批准可治疗较严重阿尔茨海默病的药物。美金刚为Ｎ－甲基－Ｄ－天门冬氨酸（ＮＭＤＡ）受体拮抗剂，可通过阻断谷氨酸盐的作用而缓解阿尔茨海默病患者的症状。该药物使用较为安全，最常见不良反应为眩晕（７％）、头痛（６％）和便秘（６％）。

【原产地英文商品名】NAMENDA SOLUTION 10mg/5ml 360mls/bottle
【原产地英文药品名】MEMANTINE HCL
【中文参考药品译名】盐酸美金刚
【生产厂家中文参考译名】森林实验室
【生产厂家英文名】FOREST LABS
【中文参考商品译名】

·NAMENDA溶液 10毫克/5毫升 360毫升/瓶

·NAMENDA滴定包装 5毫克*28片+10毫克*21片,49片/板装

·NAMENDA 5毫克/片 100片/盒
·NAMENDA 10毫克/片 30片/盒

Namenda
Generic Name: memantine (meh MAN teen)
Brand Names: Namenda, Namenda XR

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What is Namenda?
Namenda reduces the actions of chemicals in the brain that may contribute to the symptoms of Alzheimer's disease.

Namenda is used to treat moderate to severe dementia of the Alzheimer's type.

Namenda may also be used for other purposes not listed in this medication guide.

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Information about Namenda
Before using Namenda, tell your doctor if you are allergic to any drugs, or if you have a seizure disorder, cataracts, liver or kidney disease, or a bladder or kidney infection.

Namenda can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

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Before taking Namenda
Do not use Namenda if you are allergic to memantine.

Before using Namenda, tell your doctor if you are allergic to any drugs, or if you have:
epilepsy or other seizure disorder;
cataracts;
liver disease;
kidney disease; or
a bladder or kidney infection.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take Namenda.

FDA pregnancy category B. Namenda is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether Namenda passes into breast milk or if it could harm a nursing baby. Do not use Namenda without telling your doctor if you are breast-feeding a baby.

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How should I take Namenda?
Take Namenda exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results from Namenda.

Take this medicine with a full glass of water.

Namenda can be taken with or without food.

The liquid (oral solution) form of this medication comes with patient instructions for safe and effective use. Follow these directions carefully. Ask your doctor or pharmacist if you have any questions.

Do not mix the oral solution with any other liquids.

Rinse the empty oral syringe with clean water and allow it to air dry after every use.

Namenda XR capsules can be taken intact or may be opened, sprinkled on applesauce, and then swallowed. The entire contents of each Namenda XR capsule should be consumed.

Except when opened and sprinkled on applesauce, as described above, Namenda XR should be swallowed whole. Namenda XR capsules should not be divided, chewed, or crushed.

It is important to use Namenda regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

To be sure this medication is helping your condition, and is not causing harmful effects, doctor will need to check your progress on a regular basis. Do not miss any scheduled appointments.

Store Namenda at room temperature away from moisture and heat. Keep the liquid medicine bottle tightly closed with the cap provided. Do not store the bottle with the oral syringe in it.

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What happens if I miss a dose?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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What happens if I overdose?
Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include restlessness, drowsiness, unusual behavior, hallucinations, feeling light-headed, or fainting.

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What should I avoid while taking Namenda?
Namenda can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

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Namenda side effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using Namenda and call your doctor at once if you have any of these serious side effects:
cough, chest tightness, fever, trouble breathing;
chest pain, fast heart rate;
confusion, hallucinations;
sudden numbness or weakness, especially on one side of the body;
lack of coordination;
fainting or seizure (convulsions);
urinating less than usual or not at all;
pale skin, easy bruising or bleeding, unusual weakness; or
increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure).

Less serious side effects may include:
nausea, vomiting, diarrhea, constipation, loss of appetite;
dizziness, tired feeling;
weight loss;
swelling in your hands or feet;
fast heart rate;
easy bruising or bleeding, unusual weakness;
joint pain;
anxiety, aggression;
skin rash;
redness or swelling of or around your eyes; or
urinating more than usual.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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What other drugs will affect Namenda?
Before taking Namenda, tell your doctor if you are using any of the following drugs:
cimetidine (Tagamet);
nicotine (Commit, Habitrol, Nicoderm, Nicotrol, Nicorette);
ranitidine (Zantac);
quinidine (Cardioquin, Quinadex, Quinaglute);
sodium bicarbonate (Alka-Seltzer, baking soda antacid home remedy);
antiviral medication such as amantadine (Symmetrel) or rimantadine (Flumadine);
cold or cough medicine that contains dextromethorphan;
a diuretic (water pill) such as hydrochlorothiazide (HCTZ, HydroDiuril, Hyzaar, Lopressor, Vasoretic, Zestoretic) or triamterene (Dyrenium, Maxzide, Dyazide);
medicine to treat glaucoma, such as acetazolamide (Diamox), dichlorphenamide (Daranide), or methazolamide (Neptazane, MZM, Glauctabs); or
an oral diabetes medicine that contains metformin (such as Fortamet, Glucophage, Actoplus Met, Avanda met, Metaglip, Glucovance).

This list is not complete and there may be other drugs that can interact with Namenda. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

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Where can I get more information?
Your pharmacist can provide more information about Namenda.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.