MESNEX可与环磷酰胺或异环磷酰胺所产生的毒性代谢产物丙烯酸结合形成无毒的化合物，经尿道排出，因而避免了膀胱炎的发生。 本品可防止用高剂量异环磷酰胺或环磷酰胺进行肿瘤化疗时，引起的出血性膀胱炎等泌尿系统上皮毒性。与抗肿瘤化疗药异环磷酰胺或环磷酰胺合同，作为泌尿系统保护剂。
批准日期：2002年3月21日 公司：百特医疗
MESNEX(美斯奈[mesna])片，口服
MESNEX(美斯奈[mesna])注射液，用于静脉注射
美国最初批准:1988年
作用机制
Mesna与尿毒异环磷酰胺代谢物丙烯醛和4-羟基异环磷酰胺发生化学反应，产生解毒作用。解毒过程的第一步是mesna与4-羟基异环磷酰胺结合形成一种无尿毒性的4-磺乙基硫磷酰胺。Mesna还与丙烯醛和其他尿毒代谢物的双键结合，抑制它们对膀胱的作用。
适应症和用法
MESNEX是一种可预防异环磷酰胺引起的出血性膀胱炎的细胞保护剂。
使用限制:
MESNEX并不能降低其他病理条件如血小板减少引起的血尿风险。
剂量和管理
MESNEX可以按照三次静脉注射或单次注射的分步给药计划给药，随后口服两次MESNEX片，如下图所示。给药计划应在给药的每一天重复。在调整异环磷酰胺用量时，应维持美奈司与异环磷酰胺的比例。
静脉注射剂量的时间表:
            0小时     4小时    8小时
异环磷酰胺  1.2g/m2    --       --
MESNEX注入  240mg/m2  240mg/m2 240mg/m2
静脉和口服给药时间表:
            0小时     2小时    6小时
异环磷酰胺 1.2g/m2      --       -- 
MESNEX注入 240mg/m2     --       --
MESNEX片剂    --      480mg/m2  480mg/m2
根据异环磷酰胺治疗的需要，保持足够的尿量，监测尿中是否有血尿。
剂型和强度
•注射:1g(100mg/mL)多剂量瓶
•片剂:400毫克，功能评分
禁忌症
•已知对MESNEX或任何赋形剂(包括苄醇)过敏。
警告和预防措施
•过敏反应:有过敏反应的报道。不太严重的过敏反应也可能发生。监测病人。如果出现反应，停止美奈司，并提供支持性护理。
·皮肤毒性:出现皮疹伴嗜酸性粒细胞增多及全身症状，斯蒂文斯-约翰逊综合征，中毒性表皮坏死松解。皮疹、荨麻疹和血管性水肿也可见。监测病人。如果出现反应，停止美奈司，并提供支持性护理。
•苯甲醇毒性:防腐剂苯甲醇与新生儿和早产儿的严重不良反应和死亡有关。避免在新生儿、早产儿和低出生体重婴儿中使用。
•实验室检测改变:尿酮检测呈假阳性，酶促CPK活性检测受到干扰。
不良反应
异环磷酰胺给药后最常见的不良反应(>%)为恶心、呕吐、便秘、白细胞减少、疲劳、发热、厌食、血小板减少、贫血、粒细胞减少、腹泻、无力、腹痛、头痛、脱发、嗜睡。
如需报告疑似不良反应，请致电巴克斯特医疗保健(Baxter Healthcare)(电话:1-866-888-2472)，或致电FDA(电话:1-800-FDA-1088)或www.fda.gov/medwatch
在特定人群中使用
•妊娠期:仅在明确需要时使用。
•哺乳期母亲:女性在治疗期间不应母乳喂养。
•老年使用:剂量选择应谨慎。
如何提供/储存和处理
MESNEX(mesna)注射液100mg/mL
•NDC 0338-1305-01
1克多剂量瓶，1盒10毫升
•NDC 0338-1305-03
1克多剂量瓶，每盒10瓶10毫升
商店在20°C到25°C (68°F (77°F),游览允许15°C到30°C (59°F到86°F)(见USP控制室温)
MESNEX(mesna)平板电脑
•NDC 67108-3565-9
400毫克刻痕片包装在每盒10片
商店在20°C到25°C (68°F (77°F),游览允许15°C到30°C (59°F到86°F)(见USP控制室温)
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MESNEX 400 MG TAB 10  MESNA  BAXTER MED  NDC：67108356509 $1,512.23
MESNEX 400MG TAB BLST-PAK BA 10/PAC    MESNA  BAXTER PHARMACEUTICALS NDC：67108-3565-09  $2,593.79
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详细资料请参考原处方资料：
https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4a51ffdb-f59f-4e02-b3c4-f3457ab7b514
Mesnex
General Information
Mesnex Tablets are approved for use as a detoxifying agent to inhibit the hemorrhagic cystitis induced by Ifex (ifosfamide). This condition involves bladder problems, such as irritation due to blood being in the urine. Ifex is an antineoplastic drug used for treatment of testicular cancer. Along with Ifex, Mesnex Injection was approved for use in 1988.
Mesnex Tablets are to be used in a dosing regimen with Ifex and Mesnex Injection. If only using Mesnex Injection, the dosing regimen lasts eight hours. With the addition of Mesnex Tablets, it is reduced to six hours. Tablets also allow for quicker administration that can easily be done if not at home.
Clinical Results
Approval of Mesnex Tablets is supported by two clinical studies with over 100 cancer subjects receiving Ifex. Trials compared three intravenous doses of Mesnex to an initial intravenous dose followed by two oral doses for the prevention of hemorrhagic cystitis induced by treatment with Ifex. Both dosing regimens successfully reduced incidences of grade three or four hematuria, the primary efficacy endpoint.
Mesnex Tablets are given orally two and six hours after the co-administartion of Ifex and Mesnex Injection. Mesnex should only be prescribed along with Ifex.
Side Effects
Adverse effects associated with the use of Mesnex may include (but are not limited to) the following:
Nausea
Vomiting
Fatigue
Constipation
Leukopenia
Anemia
Asthenia
Because Mesnex is used in combination with Ifex, it is difficult to distinguish the adverse reactions which may be due to Mesnex from those caused by Ifex.
Mechanism of Action
Mesnex (mesna) was developed as a prophylactic agent to reduce the risk of hemorrhagic cystitis induced by Ifex (ifosfamide). Mesna is rapidly oxidized to its major metabolite, mesna disulfide, which then remains in the intravascular compartment and is rapidly eliminated by the kidneys. In the kidney, mesna disulfide is reduced to mesna, which reacts with the urotoxic ifosfamide metabolites, resulting in their detoxification. (From Mesnex Prescribing Information)