Drug nomenclature

The earliest roots of standardization of generic names for drugs began with city pharmacopoeias, such as the London, Edinburgh, Dublin, Hamburg, and Berlin Pharmacopoeias. The fundamental advances in chemistry during the 19th century made that era the first time in which what we now call chemical nomenclature, a huge profusion of names based on atoms, functional groups, and molecules, was necessary or conceivable. In the second half of the 19th century and the early 20th, city pharmacopoeias were unified into national pharmacopoeias (such as the British Pharmacopoeia, United States Pharmacopeia, Pharmacopoeia Germanica (PhG or PG), Italian Pharmacopeia, and Japanese Pharmacopoeia) and national formularies (such as the British National Formulary, the Australian Pharmaceutical Formulary, and the National Formulary of India). International pharmacopeias, such as the European Pharmacopoeia and the International Pharmacopoeia of the World Health Organization (WHO), have been the next level.

In 1953 the WHO created the International Nonproprietary Name (INN) system, which issues INNs in various languages, including Latin, English, French, Spanish, Russian, Chinese, and Arabic. Several countries also have national-level systems for creating generic drug names, including the British Approved Name (BAN) system, the Australian Approved Name (AAN) system, the United States Adopted Name (USAN) system (which is mostly the same as the United States Pharmacopeia (USP) system), and the Japanese Accepted Name (JAN) system. At least several of these national-level Approved Name/Adopted Name/Accepted Name systems were not created until the 1960s, after the INN system already existed. In the 21st century, increasing globalization is encouraging maximal rationalization for new generic names for drugs, and there is an increasing expectation that new USANs, BANs, and JANs will not differ from new INNs without special justification.

During the first half of the 20th century, generic names for drugs were often coined by contracting the chemical names into fewer syllables. Such contraction was partially, informally, locally standardized, but it was not universally consistent. In the second half of the 20th century, the nomenclatural systems moved away from such contraction toward the present system of stems and affixes that show chemical relationships.

Biopharmaceuticals have posed a challenge in nonproprietary naming because unlike smaller molecules made with total synthesis or semisynthesis, there is less assurance of complete fungibility between products from different manufacturers. Just as wine may vary by strain of yeast and year of grape harvest, so each product can be subtly different because living organisms are an integral part of production. The WHO MedNet community continually works to augment its system for biopharmaceuticals to ensure continued fulfillment of the goals served by having nonproprietary names.[7] In recent years the development of the Biological Qualifier system has been an example.[7]

The prefixes and interfixes have no pharmacological significance and are used to separate the drug from others in the same class. Suffixes or stems may be found in the middle or more often the end of the drug name, and normally suggest the action of the drug. Generic names often have suffixes that define what class the drug is.[2]

More comprehensive lists can be found at the National Library of Medicine's Drug Information Portal[8] or in Appendix VII of the USP Dictionary.

If the name of the drug solanezumab were to be broken down, it would be divided into two parts like this: solane-zumab. -Zumab is the suffix for humanized monoclonal antibody.[10] Monoclonal antibodies by definition contain only a single antibody clone and have binding specificity for one particular epitope.[16] In the case of solanezumab, the antibody is designed to bond to the amyloid-β peptides which make up protein plaques on the neurons of people with Alzheimer's disease.

See also Time release technology > List of abbreviations for formulation suffixes.

For combination drug products—those with two or more drugs combined into a single dosage form—single nonproprietary names beginning with "co-" exist in both British Approved Name (BAN) form and in a formerly maintained USP name called the pharmacy equivalent name (PEN). Otherwise the two names are simply both given, joined by hyphens or slashes. For example, suspensions combining trimethoprim and sulfamethoxazole are called either trimethoprim/sulfamethoxazole or co-trimoxazole. Similarly, co-codamol is codeine-paracetamol (acetaminophen), and co-triamterzide is triamterene-hydrochlorothiazide. The USP ceased maintaining PENs, but the similar "co"-prefixed BANs are still current.

Most commonly, a nonproprietary drug name has one widely agreed pronunciation in each language. For example, doxorubicin is consistently /ˌdɒksoʊˈruːbɪsɪn/ in English.[17][18] Trade names almost always have one accepted pronunciation, because the sponsoring company who coined the name has an intended pronunciation for it.

However, it is also common for a nonproprietary drug name to have two pronunciation variants, or sometimes three. For example, for paracetamol, both /ˌpærəˈsiːtəmɒl/ and /ˌpærəˈsɛtəmɒl/[18] are common, and one medical dictionary gives /pæˌræsɪˈtæmɒl/.[19]

Some of the variation comes from the fact that some stems and affixes have pronunciation variants. For example, the aforementioned third (and least common) pronunciation for paracetamol reflects the treatment of the acet affix as /ˈæsɪt/ rather than /əˈsiːt/ (both are accepted for acetyl[19][17]).

The World Health Organization does not give suggested pronunciations for its INNs, but familiarity with the typical sounds and spellings of the stems and affixes often points to the widely accepted pronunciation of any given INN. For example, abciximab is predictably /æbˈsɪksɪmæb/, because for INNs ending in -ciximab, the /ˈsɪksɪmæb/ sound is familiar. The United States Pharmacopeia gives suggested pronunciations for most USANs in its USP Dictionary, which is published in annual editions. Medical dictionaries give pronunciations of many drugs that are both commonly used and have been commercially available for a decade or more, although many newer drugs or less common drugs are not entered. Pharmacists also have access to pronunciations from various clinical decision support systems such as Lexi-comp.