Zantac即善卫得，为阻织胺H2-受体拮抗剂。能抑制基础胃酸和刺激引起的胃酸分泌，可使胃酸减少，胃蛋白酶活性降低而且具有速效和长效的特点。 常用于治疗消化性溃疡、返流性食管炎、佐林格-埃利森综合征及上消化道出血等。
【中文名】：善胃得糖浆 　　
【英文名】：Zantac 　　
【类别】：抗消化性溃疡药 　　
【别名】善胃得，呋喃硝胺、盐酸雷尼替丁 　　
【药理毒理】本品为阻织胺H2-受体拮抗剂。能抑制基础胃酸和刺激引起的胃酸分泌，可使胃酸减少，胃蛋白酶活性降低而且具有速效和长效的特点。 　　
【药动学】口服tmax约1～3h，生物利用度约49%。t1/2约2.1～3.1h。大部分以原形经肾脏排泄。本药生物利用度稳定在50%左右。口服150 mg后，2-3小时达到峰浓度，通常在300-550 ng/mL之间，其血药浓度与剂量成正比。本药不被广泛代谢。主要经肾小管分泌而消除。消除半衰期为2-3小时。静脉注射后剂量的93%经尿排出，5%在粪便排出 ；口服剂量的60-70%经尿排出，25%在粪便排出。静脉注射剂量的70%和口服剂量的35%以药物原形排出。口服和静脉给药后的代谢相似 ；剂量的6%在尿中以N-氧化物，2%以S-氧化物，2%以去甲基雷尼替丁以及1-2%以糖酸衍生物形式消除。本药作用时间相对持久，所以单剂量150 mg可有效地抑制胃酸分泌长达12小时。 　　
【适应证】消化性溃疡、返流性食管炎、佐林格-埃利森综合征及上消化道出血等。 　　
【不良反应】常见头痛及眩晕。可引起ALT可逆性升高(雷尼替丁肝炎)。偶有发热、男性乳房发育、肾炎及静注部位瘙痒、发红等。 　　
【相互作用】与茶碱类药物合用可使其血浓度升高,可减少伊曲康唑、酮康唑、头孢呋辛、地西泮等药的吸收。
【用法用量】口服，0.15g/次，2次/日，早晚饭时服；或0.3g睡前顿服；维持剂量为0.15g，睡前顿服。佐林格-埃利森综合征宜用大剂量，600mg～1200mg/日。肌注或缓慢静注，25mg～50mg/次，每4～8h 1次。静滴，100mg～300mg。儿童：口服，每次2mg/kg，3次/日。
成人十二指肠溃疡和良性胃溃疡 :急性期治疗 ：标准剂量为150 mg，每日2次，或夜间服300 mg。大部分病人在4周内愈合，少部分在8周内愈合。十二指肠溃疡病人，用300 mg/次，每日2次的治疗方案，4周的治愈率高于150 mg/次，每日2次或夜间服300 mg的方案，剂量增加并不引起不良反应发生率增加。长期治疗 ：通常采用夜间服150 mg/日。
非甾体类抗炎药引起的消化性溃疡: 急性期治疗 ：150 mg，每日2次或夜间服300 mg。疗程8-12周。预防 ：在非甾体类抗炎药治疗的同时，服用150 mg，每日2次或夜间服300 mg。 手术后溃疡 150 mg，每日2次，绝大部分病人于4周内治愈，未能完全治愈的病人通常在接下来的4周愈合。 胃-食管反流性疾病 急性反流性食管炎 ：150 mg，每日2次或夜间服300 mg，治疗8-12周。
中度至严重食管炎 ：剂量可增加至150 mg，每日4次，治疗12周。
反流性食管炎的长期治疗 ：成人 150 mg口服，每日2次。 卓-艾综合征 初期150 mg，每日3次，如需要可增加剂量，病人可很好地耐受高达6 g/日的剂量。
 间歇性发作性消化不良 :标准剂量为150 mg，每日2次，治疗6周。预防重病患者的应激性溃疡出血或消化性溃疡引起的反复出血，一旦患者可恢复进食，可用150 mg，每日2次，以替代注射给药。
Mendelsons综合征的预防: 于麻醉前2小时服150 mg，和最好前一天晚服150 mg。也可用注射剂。产科分娩病人可服用150 mg，每6小时一次。如需要全身麻醉，应另外给予非颗粒的抗酸剂(如枸橼酸钠)。
儿童消化性溃疡 2 -4 mg/kg体重/次，每日2次，最高剂量为300 mg/日。严重肾功能损害病人(肌酐清除率小于50 mL/分) 150 mg/日。长期非卧床腹透或长期血透的病人，于透析后应立即口服150 mg。 　　
【注意事项】对本药过敏者及有急性卟啉症病史者禁用。妊娠B类。肝肾功能降低者应调整剂量。胃溃疡病人在开始治疗前应排除恶性肿瘤的可能性，因为本药可掩饰胃癌的症状。本药与非甾体抗炎药同时服用者，应定期进行检查，特别是老年人和有消化性溃疡史的病人。

【原产地英文商品名】ZANTAC SYRUP 15mg/ml 480mls/bottle
【原产地英文药品名】RANITIDINE HCL
【中文参考商品译名】善胃得糖浆 15毫克/毫升 480毫升/瓶
【中文参考药品译名】盐酸雷尼替丁
【生产厂家中文参考译名】葛兰素史克
【生产厂家英文名】GLAXOSMITHKLINE
Zantac
Generic Name: ranitidine (ra NI ti deen)
Brand names: Taladine, Zantac

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What is Zantac?
Zantac (ranitidine) belongs to a group of drugs called histamine-2 blockers. Zantac works by reducing the amount of acid your stomach produces.

Zantac is used to treat and prevent ulcers in the stomach and intestines. It also treats conditions in which the stomach produces too much acid, such as Zollinger-Ellison syndrome. Zantac also treats gastroesophageal reflux disease (GERD) and other conditions in which acid backs up from the stomach into the esophagus, causing heartburn.

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

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Important information about Zantac
Using Zantac may increase your risk of developing pneumonia. Symptoms of pneumonia include chest pain, fever, feeling short of breath, and coughing up green or yellow mucus. Talk with your doctor about your specific risk of developing pneumonia.

Do not use Zantac if you are allergic to ranitidine.

Ask a doctor or pharmacist if it is safe for you to take this medicine if you have kidney disease, liver disease, or porphyria.

Heartburn is often confused with the first symptoms of a heart attack. Seek emergency medical attention if you have chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, and a general ill feeling.

Zantac granules and effervescent tablets must be dissolved in water before you take them. Your doctor may recommend an antacid to help relieve pain. Carefully follow your doctor's directions about the type of antacid to use, and when to use it. Avoid drinking alcohol. It can increase the risk of damage to your stomach. It may take up to 8 weeks of using Zantac before your ulcer heals. For best results, keep using the medication as directed. Talk with your doctor if your symptoms do not improve after 6 weeks of treatment.

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Before using Zantac
Do not use Zantac if you are allergic to ranitidine.

Heartburn is often confused with the first symptoms of a heart attack. Seek emergency medical attention if you have chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, and a general ill feeling.

Ask a doctor or pharmacist if it is safe for you to take Zantac if you have:
kidney disease;
liver disease; or
porphyria.

FDA pregnancy category B. Zantac is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Ranitidine passes into breast milk. Do not take Zantac without telling your doctor if you are breast-feeding a baby.

Using Zantac may increase your risk of developing pneumonia. Symptoms of pneumonia include chest pain, fever, feeling short of breath, and coughing up green or yellow mucus. Talk with your doctor about your specific risk of developing pneumonia.

The Zantac effervescent tablet may contain phenylalanine. Talk to your doctor before using this form of ranitidine if you have phenylketonuria (PKU).

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How should I take Zantac?
Take Zantac exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Your doctor may recommend an antacid to help relieve pain. Carefully follow your doctor's directions about the type of antacid to use, and when to use it.

Do not crush, chew, or break the Zantac effervescent tablet, and do not allow it to dissolve on your tongue. The 25-milligram effervescent tablet must be dissolved in at least 1 teaspoon of water before swallowing. The150-milligram effervescent tablet should be dissolved in 6 to 8 ounces of water.

Allow the Zantac effervescent tablet to dissolve completely in the water, and then drink the entire mixture. If you are giving this medicine to a child, you may draw the liquid mixture into a medicine dropper and empty the dropper into the child's mouth.

Zantac granules should be mixed with 6 to 8 ounces of water before drinking.

Measure Zantac liquid with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

It may take up to 8 weeks before your ulcer heals. Keep using the medication as directed and tell your doctor if your symptoms do not improve after 6 weeks of treatment.

This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using Zantac.

Store Zantac at room temperature away from moisture, heat, and light.

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

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What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include lack of coordination, feeling light-headed, or fainting.

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What should I avoid while taking Zantac?
Avoid drinking alcohol. It can increase the risk of damage to your stomach.

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Zantac side effects
Stop using Zantac and get emergency medical help if you have any of these signs of an allergic reaction to Zantac: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop taking Zantac and call your doctor at once if you have a serious side effect such as:
chest pain, fever, feeling short of breath, coughing up green or yellow mucus;
easy bruising or bleeding, unusual weakness;
fast or slow heart rate;
problems with your vision;
fever, sore throat, and headache with a severe blistering, peeling, and red skin rash; or
nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious Zantac side effects may include:
headache (may be severe);
drowsiness, dizziness;
sleep problems (insomnia);
decreased sex drive, impotence, or difficulty having an orgasm; or
swollen or tender breasts (in men);
nausea, vomiting, stomach pain; or
diarrhea or constipation.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

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What other drugs will affect Zantac?
Before taking Zantac, tell your doctor if you are taking triazolam (Halcion). You may not be able to use Zantac, or you may need dosage adjustments or special tests during treatment.

There may be other drugs that can interact with Zantac. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.