International nonproprietary name

An International Nonproprietary Name (INN) is an official generic and nonproprietary name given to a pharmaceutical substance or an active ingredient,^[1] encompassing compounds, peptides and low-molecular-weight proteins (e.g., insulin, hormones, cytokines), as well as complex biological products, such as those used for gene therapy.^[2] INNs are intended to make communication more precise by providing a unique standard name for each active ingredient, to avoid prescribing errors.^[3] The INN system was initiated by the World Health Organization (WHO) in 1953.^[4]

Having unambiguous standard names for each pharmaceutical substance (standardization of drug 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 is citalopram. The antibacterial medication known as co-trimoxazole as well as those under the brand names Bactrim and Septran all contain two active ingredients easily recognisable by their INN: trimethoprim and sulfamethoxazole.

The WHO publishes INNs in English, Latin, French, Russian, Spanish, Arabic, and Chinese, and a drug's INNs are often cognate across most or all of the languages, with minor spelling or pronunciation differences, for example: paracetamol (en) paracetamolum (la), paracétamol (fr) and парацетамол (ru). An established INN is known as a recommended INN (rINN), while a name that is still being considered is called a proposed 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]