give rise to problems. The current edition of the British National Formulary lists several propri- Table 1-Main differences between British approved name3 and intemational non-proprietary name4 of various etary oral preparations of morphine sulphate, drugs including liquid, sustained release, and non- sustained release preparations, which may result British International non- British International non- in confusion. approved name proprietary name approved name proprietary name Confusion between sustained release and non- Acepifylline Acefylline piperazine Hydroxyurea Hydroxycarbamide sustained release morphine sulphate tablets and Acinitrazole Aminitrozole lodipamide Adipiodone morphine sulphate liquid can result in two Acrosoxacin Rosoxacin Ipodate lopodate different outcomes: high initial peak plasma con- Actinomycin C Cactinomycin Ironedetate Feredetate centrations of morphine and inadequate dura- Actinomycin D Dactinomycin Isobuzole Glysobuzole tion of analgesia will result if liquid or Adrenaline Epinephrine Lignocaine Lidocaine non-sustained release tablets are given instead of Aloxidone Allomethadione Methadyl acetate Acetylmethadol sustained release tablets, while accumulation of Ametazole Betazole Metharbitone Metharbital morphine and potential toxicity will occur with Amethocaine Tetracaine Methimazole Thiamazole repeated dosing if a sustained release tablet is Amylobarbitone Amobarbital Methohexitone Methohexital given instead of a non-sustained release prepara- Anoxynaphthonate Anazolene Methoin Mephenytoin Azetepa Azatepa Methotrimeprazine Levomepromazine tion. Balipramine Depramine Methsuximide Mesuximide There are two other potential sources of Barbitone Barbital Methyl benzoquate Nequinate confusion. Firstly, the proprietary name MST Bendrofluazide Bendroflumethiazide Methyl cysteine Mecysteine has been misinterpreted as being an abbreviation Benzathine penicillin Benzathine benzylpenicillin Methylphenobarbitone Methylphenobarbital for morphine sulphate rather than a formulation Benzhexol Trihexyphenidyl Methyprylone Methyprylon of the drug. Secondly, Oramorph liquid is also Benztropine Benzatropine Mitozantrone Mitoxantrone available in unit dose vials, which have been Bindazac Bendazac Mustine Chlormethine reported to have been confused with injectable Bismuth glycollylarsanilate Glycobiarsol Nealbarbitone Nealbarbital preparations and given intravenously or intra- Bromodiphenhydramine Bromazine Nicoumalone Acenocoumarol muscularly in error.2 Buniodyl Bunamiodyl Nitrofurazone Nitrofural To minimise such errors in our hospital we Bupropion Amfebutamone Noradrenaline Norepinephrine Buthalitone Buthalital Norbutrine Norbudrine aim to ensure that prescriptions for solid oral Butoxamine Butaxamine Octacosactrin Tosactide formulations of morphine sulphate include both Carbolonium Hexcarbacholine Oxethazaine Oxetacaine the brand name and the approved name-for Chlophedianol Clofedanol Oxpentifylline Pentoxifylline example, morphine sulphate sustained release Chlorbutol Chlorobutanol Pentacosactride Norleusactide (MST) or morphine sulphate (Sevredol). When Chlordantoin Clodantoin Pentaerythritol Pentaerithrityl these items are dispensed by the pharmacy, the Chlorfenvinphos Clofenvinfos Pentobarbitone Pentobarbital containers are labelled with both the proprietary Chlorhexadol Chloralodol Pentolinium Pentolonium and approved names. As the liquid morphine Chlormethiazole Clomethiazole Phanquone Phanquinone sulphate preparation listed in our formulary is Chlorpheniramine Chlorphenamine Phenobarbitone Phenobarbital Oramorph liquid (not in unit dose vials) we have Colistin sulphomethate Colistimethate Phenyl aminosalicylate Fenamisal decided not to include Oramorph sustained Cyclobarbitone Cyclobarbital Plasmin Fibrinolysin Cysteamine Mercaptamine Polyoxyl (8,40) stearate Macrogol ester release tablets, to minimise potential confusion Deoxycortone Desoxycortone Povidone Polyvidone between liquid and tablet formulations. Desferrioxamine Deferoxamine Pramoxine Pramocaine The guidelines put forward by the expert Diamthazole Dimazole Promethoestrol Methestrol working group will aid decision making in the Diatrizoate Amidotrizoate Proquamezine Aminopromazine prescribing of analgesics. Doctors and pharma- Diazinon Dimpylate Quinalbarbitone Secobarbital cists, however, have an important role in Dichlorphenamide Diclofenamide Rolicypram Rolicyprine ensuring that the range ofproducts available and Dicyclomine Dicycloverine Secbutobarbitone Secbutabarbital the accuracy with which the prescription is writ- Diethylpropion Amfepramone Solapsone Solasulfone ten reduce to a minimum the risk of patients Dipenine Diponium Stanolone Androstanolone receiving the wrong formulation of morphine Dipyrone Metamizole Stilboestrol Diethylstilbestrol sulphate. Dothiepin Dosulepin Streptonicozid Streptoniazid GILLIAN F CAVELL Dyclocaine Dyclonine Sulfametopyrazine Sulfalene Principal pharmacist Epithiazide Epitizide Sulphaurea Sulfacarbamide King's College Hospital, Ethopropazine Profenamine Tetracosactrin Tetracosactide London SE5 9RS Ethybenztropine Etybenzatropine Tetrahydrozoline Tetryzoline Fenchlorphos Fenclofos Thiacetazone Thioacetazone 1 Expert Working Group ofthe European Association for Pallia- tive Care. Morphine in cancer pain: modes of administra- Fluopromazine Triflupromazine Thialbarbitone Thialbarbital tion. BMJ 1996;312:823-6. (30 March.) Flurandrenolone Fludroxycortide Thiopentone Thiopental 2 Cousins D, Upton D. Medication errors. Oral solutions can be Frusemide Furosemide Thymoxamine Moxisylyte injected. Pharmacy in Practice 1995;5:76-7. Gestronol Gestonorone Triacetyloleandomycin Troleandomycin Glycalox Glucalox Tribavirin Ribavirin Halopyramine Chloropyramine Trimeprazine Alimemazine Heptabarbitone Heptabarb Trimustine Trichlormethine Naming of drugs Hexachlorophane Hexachlorophene Troxidone Trimethadione Hexamine Methenamine Vinbarbitone Vinbarbital Differences between nomenclatures are Hexobarbitone Hexobarbital Vinylbitone Vinylbital much greater than editorial suggested Hydroxamethocaine Hydroxytetracaine Viprynium Pyrvinium ED1TOR, C F George discusses the difficulties that will result from the European Commission's includes some widely used drugs, such as name.5 This may be the same as the international directive which states that the international actinomycin D, bupropion, chlorpheniramine, non-proprietary name but different from the non-proprietary name, not the British approved dipyrone, hydroxyurea, nicoumalone, plasmin, British approved name (for example, phenobarbi- name, must appear on the labels and leaflets of povidone, and thiopentone. tal) or vice versa (povidone), or it may be different medicinal products from January 1998.' George The World Health Organisation's inter- from both of these (for example, isoproterenol, underestimates the problem, however, in asserting national non-proprietary name programme was whose British and international name is isoprena- that "in total, 41 drugs have a British approved implemented to overcome this problem of syno- line). In extreme cases the same drug has three name that is significantly different to their nyms. In practice, however, it has not achieved names, as with aminitrozole, whose British recommended international non-proprietary this objective, fundamentally because no single approved name is acinitrazole and United States name." I recently reviewed this issue and compared official organ is responsible for selecting the valid approved name is nithiamide). In the European the official listings of the British approved names terms. The World Health Organisation publishes Union, which has 11 official languages, the and the international non-proprietary names.2 If the international non-proprietary names in five situation is more complex, because several we ignore differences in spelling, such as languages (Latin, English, French, Spanish, and countries have their own list of approved names. cyclosporin (whose international non-proprietary Russian), but many developed countries have Whatever solution is adopted as a result of the name is ciclosporin) and oestradiol (estradiol), the their own nomenclature committees. new directive in 1998, clearly none of the mem- number of important differences between the two In the English speaking world, for example, the ber states ofthe European Union can, in the long nomenclatures is well over 100 (table 1); this figure United States has its own United States adopted term, expect to maintain an official name differ- 688 BMJ VOLUME 313 14 SEPTEMBER 1996 ent from the international non-proprietary 1 George CF. Naming of drugs: pass the epinephrine, please. quoted) and the values do not seem to be BMJ 1996;312:1315-6. (25 May.) name. On the other hand, the World Health 2 Hawton K, Fagg J. Trends in deliberate self poisoning and self compatible with the syndrome of inappropriate Organisation cannot impose on these countries a injury in Oxford, 1976-90. BM, 1992;304:1409-1 1. secretion of antidiuretic hormone. Instead, they name that they consider to be unacceptable. The 3 Spooner JB, Harvey JG. Paracetamol overdosage-facts not suggest more that simple (severe) water intoxica- most logical solution would be to set up bilateral misconceptions. Pharm J 1993;250:706-7. tion was the cause of cerebral oedema. 4 Reynolds JEF, ed. Martindale: the extra pharmacopoeia, 31st ed. discussions between the organisation's experts London: Pharmaceutical Press, 1996. T M COOK and the national nomenclature committees with 5 Ritter JM, Lewis LD, Mant