英文药名: Proloprim(trimethoprim tablets)

中文药名: 甲氧苄啶片

药品名称

通用名称：甲氧苄啶
英文名：Trimethoprim
其它中文名：甲氧苄氨嘧啶、甲氧苄胺嘧啶、甲氧苄嘧啶、三甲氧苄胺嘧啶、三甲氧苄啶
其它英文名：Proloprim、Trimethoxyprim、Trimpex
规格

甲氨苄啶片0.1g，0.2g。
药理作用

药效学
本品属抑菌剂，为亲脂性弱碱，化学结构属乙胺嘧啶类。其抗菌作用原理为干扰细菌的叶酸代谢。主要为选择性抑制细菌的二氢叶酸还原酶的活性，使二氢叶酸不能还原为四氢叶酸，而合成叶酸是核酸生物合成的主要组成部分，因此本品阻止了细菌核酸和蛋白质的合成，且甲氧卡啶(TMP)与细菌的二氢叶酸还原酶的结合较之对哺乳类动物酶的结合紧密 5～6万倍。本品与磺胺药的合用可使细菌的叶酸合成代谢遭到双重阻断，有协同作用，使磺胺药抗菌活性增强，并可使抑菌作用转为杀菌作用，减少耐药菌株。
药动学
本品口服后吸收完全，约可吸收给药量的 90％以上，血高峰浓度在给药后 1～4小时到达。口服 0.1g高峰血药浓度约为 1μg/ml。本品吸收后广泛分布至组织和体液，在肾、肝、脾、肺、肌肉、支气管分泌物、唾液、阴道分泌物、前列腺组织及前列腺液中的浓度均超过血药浓度。本品可穿过血脑屏障至脑脊液中，脑膜无炎症时脑脊液药物浓度为血药浓度的 350％，炎症时可达 50～100％。TMP亦可穿过血胎盘屏障，胎儿循环中药物浓度接近母体血药浓度。乳汁中本品浓度接近或高于血药浓度。房水中药物浓度约为血药浓度的 l/3。本品表观分布容积为 1.2～2.2L/kg；蛋白结合率为 30～46％；Ｔ1/2为 8～10小时，无尿时 20～50小时。TMP主要自肾小球滤过，肾小管分泌排出，24小时约可排出给药量的 40～60％，其中 80～90％以药物原形排出，而其余部分以代谢物形式排出。平均尿药浓度为 90～100μg/ml，尿中高峰浓度约为 200μg/ml。在酸性尿中本品自尿排泄增加，碱性尿中排出减少。本品少量自胆汁及粪便中(约为给药量的 4％)排出。
适应症　

适用于对其呈现敏感的大肠杆菌、奇异变形杆菌、肺炎杆菌和某些肠杆菌属和腐生葡萄球菌等细菌所致的急性单纯性尿路感染。本品对绿脓杆菌感染无效。
用法用量　　

口服，一次 0.1g，每 12小时一次。
成人患者有肾功能损害者需减量应用。肌酐清除率每分钟＞30ml仍用成人常用量；肌酐清除率每分钟在 15—30ml，每 12小时服 50mg；肌酐清除率每分钟＜15ml者不得用本品。或遵医嘱！
禁用/慎用　

(1)本品可穿过血胎盘屏障，虽然在人类中该药的应用尚未证实有问题存在，但由于 TMP对大鼠、兔有致畸作用，其作用机制为干扰叶酸代谢，在胎儿循环及羊水中药物浓度接近母体血药浓度，因此本品在妊娠期间应用必须权衡利弊。
(2)本品可分泌至乳汁中，其浓度较高，且药物有可能干扰哺乳婴儿的叶酸代谢，因此虽然在人类中尚未证实其问题存在，但本品对乳母的应用必须权衡利弊。
(3)早产儿、新生儿不宜应用本品。
(4)下列情况应慎用；肝功能损害；由于叶酸缺乏的巨细胞生成性贫血或其他血液系统疾病；肾功能损害。
孕妇禁用。早产儿、新生儿避免使用。严重肝、肾疾病、血液病(如白细胞减少、血小板减少、紫癜症等)禁用。
给药说明　　

本品可空腹服用，如有胃肠道刺激症状时也可与食物同服。
如 TMP引起叶酸缺乏时，可同时服用叶酸制剂，后者并不干扰 TMP的抗菌活性，因细菌并不能利用已合成的叶酸。如有骨髓抑制征象发生，应即停用 TMP，并给予叶酸 3—6mg肌注每日 1次，使用 3日或根据需要用药至造血功能恢复正常，对长期、过量使用本品者可给予高剂量叶酸并延长疗程。
无尿患者本品的半衰期可自 10小时左右延长至 20—50小时。
TMP可自血液透析中被清除，故在透析后需补给维持量的全量；腹膜透析对本品自血中清除无影响。
用药期间应定期进行周围血象检查，在疗程长、服用剂量大、老年、营养不良及服用抗癫痫药者易出现叶酸缺乏症，如周围血象中白细胞或血小板等已有明显减少则需停用本品。
不良反应　

(1)由于本品对叶酸代谢的干扰可产生血液系统不良反应，可出现白细胞减少，血小板减少或正铁血红蛋白性贫血，表现为继发感染后的发热、咽痛、异常的出血或青肿、疲劳、无力、气急等。一般白细胞及血小板减少系轻度，及时停药可望恢复，也可加用叶酸制剂。
(2)过敏反应，可发生瘙痒、皮疹。
(3)恶心、呕吐、腹泻等胃肠道反应，一般症状轻微。
可引起胃肠道反应：恶心, 呕吐, 食欲不振, 腹胀, 腹泻。可能引起过敏反应：皮疹, 药热等症状。也可有血小板及白细胞减少。长期使用或剂量过大时,应注意血象改变。
药物相互作用　

(1)本品不宜与抗肿瘤药、2，4-二氨基嘧啶类药物同时应用，也不宜在应用其他叶酸拮抗药治疗的疗程之间应用本品，因为有产生骨髓再生不良或巨幼红细胞贫血的可能。
(2)利福平与本品同时应用可明显使后者清除增加和血清半衰期缩短。
(3)与环孢素同用可增加肾毒性。
(4)本品可干扰苯妥英的肝内代谢，增加苯妥英的T1/2达 50％，并减低其清除率 30％。

Proloprim Generic Name: Trimethoprim (trye-METH-oh-prim)Brand Name: Proloprim
Proloprim is used for:
Treating infections caused by certain bacteria.
Proloprim is an antibiotic. It works by killing sensitive bacteria.
Do NOT use Proloprim if:
you are allergic to any ingredient in Proloprim or to similar medicines
you are taking dofetilide
you have anemia caused by low levels of folate in the blood
Contact your doctor or health care provider right away if any of these apply to you.
Before using Proloprim :
Some medical conditions may interact with Proloprim . Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
if you are pregnant, planning to become pregnant, or are breast-feeding
if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
if you have allergies to medicines, foods, or other substances
if you have liver or kidney problems or blood problems (eg, anemia, porphyria)
if you have or are at risk for low levels of folate in the blood (eg, you have alcoholism, are elderly, you do not absorb nutrients from food properly, you are in a poor nutritional state, you are taking medicine for seizures)
Some MEDICINES MAY INTERACT with Proloprim . Tell your health care provider if you are taking any other medicines, especially any of the following:
Dofetilide because risk of severe heart problems may be increased by Proloprim
Methotrexate, phenytoin, or sulfones (eg, dapsone) because their actions and the risk of their side effects may be increased by Proloprim
Cyclosporine because its effectiveness may be decreased and risk of liver side effects may be increased by Proloprim
This may not be a complete list of all interactions that may occur. Ask your health care provider if Proloprim may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use Proloprim :
Use Proloprim as directed by your doctor. Check the label on the medicine for exact dosing instructions.
Take Proloprim by mouth with or without food.
Proloprim works best if it is taken at the same time each day.
To clear up your infection completely, use Proloprim for the full course of treatment. Keep using it even if you feel better in a few days.
If you miss a dose of Proloprim , take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use Proloprim .

Important safety information:
Proloprim may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to Proloprim . Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
Be sure to use Proloprim for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
Proloprim only works against bacteria; it does not treat viral infections (eg, the common cold).
Long-term or repeated use of Proloprim may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
Proloprim may interfere with certain lab tests. Be sure your doctor and lab personnel know you are using Proloprim .
Lab tests, including complete blood cell counts, may be performed while you use Proloprim . These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
Use Proloprim with caution in ELDERLY; they may be more sensitive to the effects of Proloprim .
Proloprim should be used with extreme caution in CHILDREN younger than 12 years old; safety and effectiveness in these children have not been confirmed.
Use Proloprim with extreme caution in CHILDREN younger than 10 years old who have diarrhea or an infection of the stomach or bowel.
PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Proloprim while you are pregnant. Proloprim is found in breast milk. If you are or will be breast-feeding while you use Proloprim , check with your doctor. Discuss any possible risks to your baby.
Possible side effects of Proloprim :
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Nausea; skin sensitivity to sunlight; stomach upset; vomiting.
Seek medical attention right away if any of these SEVERE side effects occur:
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blistered, peeling, red, or swollen skin; bloody or black, tarry stools; chest pain; chills, fever, or sore throat; decreased urination; joint or muscle pain; irregular heartbeat; painful or stiff neck; purple patches under the skin; seizures; severe diarrhea; shortness of breath; stomach cramps/pain; unusual bruising or bleeding; unusual tiredness or weakness; unusually pale skin; vaginal irritation or discharge; yellowing of the skin or eyes.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center (http://www.aapcc.org), or emergency room immediately. Symptoms may include confusion; depression; dizziness; drowsiness; fever, chills, or sore throat; loss of consciousness; severe nausea or vomiting; severe or prolonged headache; unusual bruising or bleeding.
Proper storage of Proloprim :
Store Proloprim at room temperature, between 59 and 77 degrees F (15 and 25 degrees C). Store away from heat, moisture, and light. Keep in a tight, light-resistant container. Do not store in the bathroom. Keep Proloprim out of the reach of children and away from pets.
General information:
If you have any questions about Proloprim , please talk with your doctor, pharmacist, or other health care provider.
Proloprim is to be used only by the patient for whom it is prescribed. Do not share it with other people.
If your symptoms do not improve or if they become worse, check with your doctor.
This information is a summary only. It does not contain all information about Proloprim . If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.
Proloprim Prescribing Information (FDA)
Proloprim Advanced Consumer (Micromedex) - Includes Dosage Information
Proloprim Concise Consumer Information (Cerner Multum)
Trimethoprim Prescribing Information (FDA)
Primsol Detailed Consumer Information (PDR)