Drug Nomenclature: How Does A Drug Get Its Name?

One of the most confusing aspects of pharmacology is naming individual therapeutic agents. This is because a drug is given three names and each of these names is used in a different area of the drug industry. These names are the drug’s chemical name, generic name, and brand name.

Chemical name

Every drug is given a chemical name which is a precise description of its chemical constituents and indicates the arrangement and position of atoms or atomic groups. Chemical names are long and too cumbersome to remember. For example, Sodium [2-[(2,6-dichlorophenyl)amino]phenyl]acetate is the chemical name of diclofenac sodium, a common Nonsteroidal anti-inflammatory drug (NSAID). Because of this complexity, they are rarely used practically when prescribing except for the very simplest compounds like sodium bicarbonate, magnesium trisilicate etc.

The chemical name is important to chemists, pharmacists, and researchers who work with drugs at the chemical level.

Generic name

Drugs are also known by generic, non- proprietary or official names. This is the name given to a drug after it might have been found to be of therapeutic use. It is the name with which the drug is described in official books of reference like pharmacopoeias. It is also the name that is authoritatively accepted by a scientific body.

The scientific body may be country-specific, and hence, different countries might end up having different names for the same drug.

Read Also: Why do the effects of drugs vary between different people?

To avoid ambiguity, all member nations of the World Health Organization (WHO) signed an agreement to use a single recommended International Non-proprietary Name (rINN) for each drug. Despite the rINN agreement, due to widespread use, a few of the older drugs still have more than one non-proprietary name. Examples are shown the table below.

The generic name is easier to read and pronounce than the drug’s chemical name, for example the generic name of Sodium [2-[(2,6-dichlorophenyl)amino]phenyl]acetate is diclofenac sodium.

Brand name

The brand (also known as proprietary or trade name) is the name given to a drug by its manufacturer. A drug may have several brand names, depending on the number of manufacturers. For example, diclofenac sodium is marketed under various brand names like Voltaren SR^®, Dicloran^®, Diclocare^®, Cofenac^®, etc.

Unlike chemical and generic names, brand names are easy to remember, short, catchy and most often suggestive of the drug component.

Note: The use of generic names is now more firmly established as being more ethical and freeing the medical profession from commercial ties.

References

1. Aguwa, C. and Akah, P. (2006). How Drugs Act. In C. Aguwa and J. Ogbuokiri (Eds.), A Handbook of Pharmacology for Nursing and Allied Health Professions (pp. 2-7). Nigeria: Africana First Publishers Limited.

2. Kamienski, M. and Keogh, J. (2006). Pharmacology Demystified. New York: McGraw-Hill Companies, Inc.

3. Raj, G. and Raveendran, R. (2019). Introduction to Basics of Pharmacology and Toxicology Volume 1: General and Molecular Pharmacology: Principles of Drug Action. Singapore: Springer Nature Singapore Pte Ltd.

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