Aninternational nonproprietary name (INN) is an officialgeneric and nonproprietary name given to apharmaceutical substance or anactive ingredient,[1] encompassingcompounds,peptides and low-molecular-weightproteins (e.g.,insulin,hormones,cytokines), as well as complex biological products, such as those used forgene therapy.[2] INNs are intended to make communication more precise by providing a unique standard name for each active ingredient, to avoidprescribing errors.[3] The INN system was initiated by theWorld Health Organization (WHO) in 1953.[4]
Having unambiguous standard names for each pharmaceutical substance (standardization ofdrug nomenclature) is important because a drug may be sold under many different brand names, or a branded medication may contain more than one drug. For example, the branded medications Celexa, Celapram and Citrol all contain the same active ingredient whose INN iscitalopram. The antibacterial medication known asco-trimoxazole as well as those under the brand namesBactrim andSeptran all contain two active ingredients easily recognisable by their INN:trimethoprim andsulfamethoxazole.
The WHO publishes INNs in English,Latin, French, Russian, Spanish,Arabic, andChinese, and a drug's INNs are oftencognate across most or all of the languages, with minor spelling or pronunciation differences, for example:paracetamol (en)paracetamolum (la),paracétamol (fr) andпарацетамол (ru). An established INN is known as arecommended INN (rINN), while a name that is still being considered is called aproposed INN (pINN).[4]
National nonproprietary names such as British Approved Names (BAN), Dénominations Communes Françaises (DCF), Japanese Adopted Names (JAN) and United States Adopted Names (USAN) are nowadays, with rare exceptions, identical to the INN.[3]
MandateTheWorld Health Organization has a constitutional mandate to"develop, establish and promote international standards with respect to biological, pharmaceutical and similar products".The World Health Organization collaborates closely with INN experts and national nomenclature committees to select a single name of worldwide acceptability for each active substance that is to be marketed as a pharmaceutical. To avoid confusion, which could jeopardize the safety of patients, trade-marks should neither be derived from INNs nor contain common stems used in INNs.
Each drug's INN is unique but may contain astem that is shared with other drugs of the sameclass. In this context, a stem is a syllable (or syllables) created to evoke in the name the pharmacological mechanism of action or the chemical structure of the substance. Stems are mostly placed word-finally (suffixes), but in some cases word-initial stems (prefixes) are used. For example, thebeta blocker drugspropranolol andatenolol share the stem-olol (as asuffix), and the benzodiazepine drugslorazepam anddiazepam share the stem-azepam (also a suffix) The list of stems in use are collected in a publication informally known as theStem Book.[5]
Some examples of stems are:
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TheSchool of INN is a WHO International Nonproprietary Name Programme initiative launched in 2019,[6] which aims to provide information to pharmacy, medical and health students, as well as health professionals and other stakeholders on how an INN is designed and constructed.[7]
Users can take self-administered courses on several topics using this free and open source learning platform. For example, the courseAn Introduction to Drug Nomenclature and INN provides the user with a general overview of drug nomenclature and how INN are obtained and constructed. The courseLearning Clinical Pharmacology (ATC classification, INN system) provides the student with the first steps to learn pharmacology usingINN stems.
Registered students can take other courses provided by the School of INN, such as theStem in a pill course, in which each topic or course contains information correlating INN and pharmacology for a given stem, includingindications,mechanism of action,pharmacokinetics,contraindications, anddrug interactions for the drugs sharing the stem.[citation needed]
There is also a"How to ..." section about INN Programme services andMedNet INN which enables users to carry out searches in the INN database to retrieve information on INN, its chemical information and ATC codes amonsgt other things.[citation needed]
The School of INN has created pilot sites in collaboration with several Universities around the globe:University of the Western Cape(South Africa),University of Eastern Piedmont (Italy),Université Grenoble Alpes (France) andUniversity Ramon Lull andUniversity of Alcalá in Spain. These pilot sites are involved in disseminating the use of INN, teaching based on INN and related research activities.[8]
The termstem is not used consistently inlinguistics. It has been defined as a form to whichaffixes (of any type) can be attached.[9] Under a different and apparently more common view, this is the definition of aroot,[10] while a stem consists of the root plus optionalderivational affixes, meaning that it is the part of a word to whichinflectional affixes are added.[11] INN stems employ the first definition, while under the more common alternative they would be described as roots.
Pharmacology andpharmacotherapy (likehealth care generally) are universally relevant around the world, makingtranslingual communication about them an important goal. Aninterlingual perspective is thus useful indrug nomenclature. The WHO issues INNs in English, Latin, French, Russian, Spanish, Arabic, and Chinese. A drug's INNs are oftencognates across most or all of the languages, but they also allow smallinflectional,diacritic, andtransliterational differences that are usually transparent and trivial for nonspeakers (as is true of mostinternational scientific vocabulary). For example, althoughibuprofenum (la) has an inflectional difference fromibuprofen (en), and althoughibuprofène (fr) has a diacritic difference, the differences are trivial; users can easily recognize the "same word". AlthoughИбупрофе́н (ru) andibuprofen (en) have a transliteration difference, they sound similar, and for Russian speakers who can recognizeLatin script or English speakers who can recognizeCyrillic script, they look similar; users can recognize the "same word". Thus, INNs make medicines bought anywhere in the world as easily identifiable as possible to people who do not speak that language. Notably, the "same word" principle allows health professionals and patients who do not speak the same language to communicate to some degree and to avoid potentially life-threatening confusions from drug interactions.
To facilitate the translation and pronunciation of INN, "f" should be used instead of "ph", "t" instead of "th", "e" instead of "ae" or "oe", and "i" instead of "y"; the use of the letters "h" and "k" should be avoided.[12] Thus a predictable spelling system, approximatingphonemic orthography, is used, as follows:
Many drugs are supplied assalts, with a cation and an anion. The way the INN system handles these is explained by theWHO at its "Guidance on INN" webpage.[1] For example,amfetamine andoxacillin are INNs, whereas various salts of these compounds – e.g.,amfetamine sulfate andoxacillin sodium – aremodified INNs (INNM).[1][13]
Several countries had created their own nonproprietary naming system before the INN was created, and in many cases, the names created under the old systems continue to be used in those countries. As one example, in English the INN name for a common painkiller isparacetamol; the table below gives the alternative names for this in different systems:
| International Nonproprietary Name (INN) | |
| Australian Approved Name (AAN) | paracetamol[14] |
| British Approved Name (BAN) | paracetamol[15] |
| Chinese Approved Drug Name (CADN) | 对乙酰氨基酚 (zh) |
| acetaminophen[15] |
| アセトアミノフェン (jp) acetaminophen (en) |
| Other generic names |
|
| Proprietary names |
|
| IUPAC name | N-(4-hydroxyphenyl)acetamide |
| ATC code | N02BE01 |
Other naming systems not listed above includeFrance'sDénomination Commune Française (DCF) andItaly'sDenominazione Comune Italiana (DCIT).[16]
In principle, INNs are selected only for the active part of the molecule which is usually the base, acid or alcohol. In some cases, the active molecules need to be expanded for various reasons, such as formulation purposes, bioavailability or absorption rate. In 1975, the experts designated for the selection of INN decided to adopt a new policy for naming such molecules. In future, names for different salts or esters of the same active substance should differ only with regard to the inactive moiety of the molecule. ... The latter are called modified INNs (INNMs).