药品名称 通用名:磷酸氯喹片 氯喹主要作用于红内期裂殖体,经48~72小时,血中裂殖体被杀灭。本品对间日疟的红外期无效,故不能根治间日疟。恶性疟则可根治。氯喹对红外期无效,对配子体也无直接作用,故不能作病因预防及中断传播之用。经氯喹作用,疟原虫的核碎裂,细胞浆出现空泡,疟色素聚成团块。已知氯喹并不能直接杀死疟原虫,但能干扰它的繁殖。本品与核蛋白有较强的结合力,通过其喹啉环上带负电的7-氯基与DNA鸟嘌呤上的2-氨基接近,使氯喹插入到DNA的双螺旋两股之间。与DNA 形成复合物,从而阻止DNA的复制与RNA的转录。氯喹还能抑制磷酸掺入疟原虫的DNA 与RNA,由于核酸的合成减少,而干扰疟原虫的繁殖。用同位素标记氯喹的实验证明,受感染的红细胞能使氯喹大量积聚其内,原虫的食物泡和溶酶体是其浓集的部位。氯喹浓集的量与食物泡内的pH有关,食物泡内的pH为酸性(分解血红蛋白最适pH为4),可导致碱性药物氯喹的浓集,该药的浓集又消耗了食物泡内的氢离子,因此更提高了食物泡内的pH值,使消化血红蛋白的血红蛋白酶受损失,疟原虫不能消化所摄取的血红蛋白,导致疟原虫生长发育所必需的氨基酸缺乏,并引起核糖核酸崩解。此外氯喹还能干扰脂肪酸进入磷脂,控制谷氨酸脱氢酶和己糖激酶等。近年来有人认为氯喹对疟原虫的早期作用是引起疟色素的凝集。疟色素的主要成分的铁原卟啉Ⅸ(FP),可以损害红细胞,并与氯喹形成复合物来介导氯喹的化疗作用。推测原虫体内具有一种或多种受体,即“FP结合物”,可能是一种白蛋白,可与 FP结合,形成无毒性的复合物,使原虫生物膜免受FP的损害。氯喹的作用机理可能是将“FP 结合物”与FP分开,并形成有毒性的氯喹-FP复合物,从而发挥其抗疟作用。由于受体改变,使氯喹失去应有的作用,这可能是疟原虫对氯喹产生抗药性的原因之一。 氯喹口服后,肠道吸收快而充分,服药后1~2小时血中浓度最高。约 55%的药物在血中与血浆成分结合。血药浓度维持较久,T1/2为2.5~10日。氯喹在红细胞中的浓度为血浆内浓度的10~20倍,而被疟原虫侵入的红细胞内的氯喹浓度,又比正常的高约25倍。氯喹与组织蛋白结合更多,在肝、脾、肾、肺中的浓度高于血浆浓度达200~700 倍。在脑组织及脊髓组织中的浓度为血浆浓度的10~30倍。氯喹在体内的代谢转化是在肝脏进行的,其主要代谢产物是去乙基氯喹,此物仍有抗疟作用。小部分(10~15%)氯喹以原形经肾排泄,其排泄速度可因尿液酸化而加快,碱化而降低。约8%随粪便排泄,氯喹也可由乳汁中排出。 用于治疗对氯喹敏感的恶性疟、间日疟及三日疟。并可用于疟疾症状的抑制性预防。也可用于治疗肠外阿米巴病、结缔组织病、光敏感性疾病(如日晒红斑)等。 1、成人常用量 (1)本品用于治疗疟疾时,不良反应较少,口服一般可能出现的反应有:头晕、头痛、眼花、食欲减退、恶心、呕吐、腹痛、腹泻、皮肤瘙痒、皮疹、甚至剥脱性皮炎、耳鸣、烦躁等。反应大多较轻,停药后可自行消失。 (1)肝肾功能不全、心脏病、重型多型红斑、血卟啉病、牛皮癣及精神病患者慎用。 孕妇禁用,哺乳期妇女慎用。 ①本品与保泰松同用,易引起过敏性皮炎; 遮光,密封保存。
Indications
This medicine is to give some degree of protection against malaria in certain countries. Some types of malaria require that you take more than one type of tablet, at the same time, to help prevent malaria. Malaria prophylaxis is recommended for non immune residents and travellers to malarious areas as these individuals have little or no immunity to malaria and risk severe attacks. You should ask your doctor or pharmacist if these are the right anti-malarials for the part of the world you are visiting. Directions Adults: Two tablets taken once a week, on the same day each week. Children: The following single dose taken once a week on the same day each week. 1-4 years Half a tablet, 5-8 years one tablet, 9-14 years one and a half tablet. Adults and children: Start You should make sure that you carefully read all product packaging and labels prior to use Ingredients Each tablet contains Chloroquine Phosphate Ph. Eur. 250mg (equivalent of 155mg of chloroquine base) The tablets contain a number of inactive ingredients which allow it to be made, these are maize starch and magnesium stearate. Side Effects As with all medicines, undesirable events are sometimes experienced. When Avloclor is used in the prevention of malaria, if used for a long time they can be serious. For Avloclor these include: Headache, stomach upset, skin rash or itch, hair discolouration or hair loss, blurring of vision or difficulty in focusing your eyes, convulsions or fits, mood changes or other effects on behaviour, changes in your blood which may make you bruise easily, get serious infections, feel very tired or breathless or may give your skin and eyes a yellow colour (due to liver problem); severe rash with peeling or blistering skin sometimes with ulceration of mucus membranes (for example, the inside of your mouth and nose). Stop taking Avloclor and contact your doctor immediately in the following situation: If you develop difficulty in breathing with or without swelling of the face, lips tongue or throat which may cause difficulty in swallowing. If you develop urticaria (itchy skin rash, nettle rah or hives). Warnings Before taking your medicine tell your doctor or pharmacist if: you have ever had problems with your liver or kidneys, you have ever been told you have porphyria or anyone in your family has, Avloclor may cause severe symptoms if you drink alcohol, you have epilepsy, or a history of convulsions, seizures, or fits, you have psoriasis (a scaly condition of the skin), you are pregnant or suspect you are pregnant, you are breast feeding (your baby will still need to be given anti-malarial treatment and you should consult your doctor or pharmacist for appropriate advice). If you suffer from any fever (high temperature) during or after visiting a country where malaria occurs, you should contact your doctor immediately. |
磷酸氯喹片(Avloclor)简介:
药品名称
通用名:磷酸氯喹片 英文名:CHLOROQUINE PHOSPHATE TABLETS 药品类别:抗疟药 性状:本品为白色片或白色糖衣片。 药理毒理
氯喹主要作用于红内期裂殖体,经48~72小时,血中裂殖体被杀灭。本品 ... 关键字:磷酸氯喹片(Avloclor)
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