TA的每日心情 | 2020-7-30 14:47 |
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Dosage nomenclature of bleomycin needs to be standardised to avoid errors
EDITOR---The consequences of errors involving anticancer drugs can be devastating. As correctly detailed by Seale, errors arise not only from inadequate time and training and supervision of medical staff but also from poorly written or ambiguous protocols.1 Such ambiguity is associated with the dosage nomenclature for bleomycin. Published protocols give bleomycin doses in milligrams (mg), international units (IU), or United States Pharmacopoeia units (USP units). This inconsistency in nomenclature seems to be universal and can lead to incorrect interpretation of medical literature.
Historically, bleomycin dosage has been described in terms of milligram potency (mg potency), in which 1 mg potency corresponded to 1 unit. In the original preparations 1 mg potency was also equivalent to 1 mg by weight (mg weight). Modifications and improvements in purification over time have meant that ampoules labelled as containing 15 mg---that is, 15 units---contained less than 15 mg weight of bleomycin.2
In 1995 labelling of bleomycin products in Australia changed from USP units to IU in line with changes in the British Pharmacopoeia and European Pharmacopoeia. The 10 mg vial, formerly labelled as containing 15 USP units, is now labelled as containing 15 000 IU. This has resulted in considerable confusion when older protocols are used or when referring to literature from the United States. Currently, the British Pharmacopoeia and European Pharmacopoeia specify 1500 IU per mg, while the United States Pharmacopoeia specifies 1.5-2 USP units per mg.2-4 Protocols that give bleomycin in mg or mg/m2 refer to mg potency, not mg weight. Therefore, 1.5-2 USP units is equivalent to 1500 IU, which is equivalent to 1 mg (by weight) or approximately 1.5 mg (by potency).
Considerable problems arise when bleomycin nomenclature is stated as mg or mg/m2. We have anecdotal evidence of patients prescribed bleomycin 30 mg as part of the bleomycin, etoposide, cisplatin protocol (BEP), erroneously receiving 45 000 IU. In the original protocol the total dose of bleomycin is specified as 30 units.5 This refers to 30 mg potency (not 30 mg weight), which is equivalent to 30 USP units or 30 000 IU.
This highlights the essential need for bleomycin dosages to be stated in terms of units (USP units in the United States or IU in Europe, the United Kingdom, and Australia), and not as mg or mg/m2. Otherwise, the risk of misinterpretation, incorrect conversion, and potential overdose of bleomycin is considerable. Standardisation of dosage nomenclature is one way of minimising errors with cytotoxic chemotherapy.
Angela Stefanou, senior pharmacist.
Drug Information Service, Peter MacCallum Cancer Institute, St Andrew's Place, East Melbourne, 3002, Australia StefanouAngela@petermac.unimelb.edu.au
Jim Siderov, senior pharmacist.
Research and Cancer Services, Austin and Repatriation Medical Centre, Heidelberg, 3084, Australia
On behalf of the Society of Hospital Pharmacists of Australia Committee of Specialty Practice in Oncology.
1. Seale JRC. Not again! BMJ 2001; 322: 548. (3 March.)
2. Parfitt K, ed. Martindale. The complete drug reference. 32nd ed. London: Pharmaceutical Press, 1999:507-509.
3. United States Pharmacopoeial Convention. The United States pharmacopoeia, 24th revision, and the national formulary, 19th ed. Rockville, MD: USPC, 1999. (With supplements.)
4. British Pharmacopoeia Commission. British pharmacopoeia. London: HMSO, 1993. (With addenda.)
5. Williams SD, Birch R, Einhorn LH, Irwin L, Greco FA, Loehrer PJ. Treatment of disseminated germ-cell tumors with cisplatin, bleomycin, and either vinblastine or etoposide. N Engl J Med 1987; 316: 1435-1440[Abstract].
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时间挺长了。。。。
中心意思:
1.过去工艺不行,1mg(实际重量)=1mg(疗效重量)=1(uint,自己理解应该是USP unit)
2.工艺提高了,1mg(实际重量)>1mg(疗效重量)=1(uint,自己理解应该是USP unit)
3.1995年,不用USP unit 改成 IU 了(英国及欧洲药典)
4.现在(作者发表时间2001年),1.5-2 USP units =1500IU=1mg(实际重量)=1.5mg(疗效重量),而Protocols(规约,不知道包不包括说明书)们mg 或 mg/m2 指的是(疗效重量)
5.他还贱贱的举个例子,说有个患者在化疗联合方案里处方30mg博**霉素,却错误的执行了45000IU,应该是30mg(疗效重量)而非30mg(实际重量),30mg(疗效重量)=30 USP units or 30 000 IU.
6.他还呼吁别乱搞了,容易出错,建议大家统一单位。
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我不是搞肿瘤专科的,只是纸上谈兵罢了。。。。。2楼和3楼都对,经检验。。。。 |
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