When I use a word . . . The languages of medicines—US proprietary names
BMJ 2024; 385 doi: https://doi.org/10.1136/bmj.q1268 (Published 07 June 2024) Cite this as: BMJ 2024;385:q1268
- Jeffrey K Aronson
- Centre for Evidence Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
- Follow Jeffrey on X (formerly Twitter): @JKAronson
Naming proprietary medicinal products
In the world of medicines, proprietary names are the brand names or trade names that pharmaceutical manufacturers give to their medicinal products. They are distinct from the generic names of the active ingredients they contain.
Regulatory guidelines on the desiderata governing a manufacturer’s choice of a proprietary name for a medicinal product were published by the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK in 20191 and the US Food and Drug Administration (FDA) did so in 2020.2 I have previously described the former.3 Here I shall describe the latter. The FDA’s document is more than twice as long as the one issued by the MHRA.
The FDA’s guidance for proprietary names of prescription drug products
It is important to stress that the recommendations listed in the FDA’s document are just that, recommendations not requirements. This is stressed by two features of the document. The first is text in a black box at the start of the document, which states that “This guidance ... is not binding on FDA or the public.” The second is the inclusion of a running head “Contains Nonbinding Recommendations.”
In the introduction to the document, the FDA states that the guidance is intended to “describe best practices to help minimize proprietary name-related medication errors.” It distinguishes between prescription medicines, for which the guidance was designed, and non-prescription medicines, for which, at the time of final publication, draft guidance had been prepared for consultation.4
The legal background to the guidance is described as the need to “avoid adoption of proprietary names that contribute to violations of the [1938] Federal Food, Drug, and Cosmetic Act (FD&C Act) and its implementing regulations.”
Following the introduction, in a long section under the heading “Background,” the FDA highlights the need for proprietary names to be sufficiently distinct to avoid confusion with existing drug names, citing the Institute of Medicine’s 1999 report, To Err is Human,5 and specifically one part of its recommendation number 7.3: “The Food and Drug Administration (FDA) should increase attention to the safe use of drugs in both pre- and postmarketing processes through the following actions: ... require pharmaceutical companies to test (using FDA-approved methods) proposed drug names to identify and remedy potential sound-alike and look-alike confusion with existing drug names.”
In a later report, Preventing Medication Errors, the Institute of Medicine encouraged the FDA “to apply the principles of cognitive and human factors engineering to the selection and evaluation of proprietary names.”6
The background section ends by describing the contents of the sections that follow: (a) evaluating aspects of the name or naming strategy that might contribute to medication errors; (b) recommendations for evaluating proposed names; and (c) evaluating names for the risk of look-alike sound-alike (LASA) problems. Here I shall deal with the first of these.
Attributes of proprietary names likely to contribute to medication errors
Similarities in spelling and pronunciation
The FDA recommends that proposed proprietary names should not be used if they are similar in spelling or pronunciation to existing names, but does not give illustrative examples. It does, however, say that it itself uses the Phonetic and Orthographic Computer Analysis (POCA) tool7 to screen proposed names, and so drug companies could clearly do the same when they formulate proposed names. Some years ago it was reported that through the use of POCA the FDA rejects about one third of all proposed names because of a potential for confusion.8 In contrast, the World Health Organization no longer uses POCA for screening INNs; it was found to be inadequate to the task because of difficulties with assessing the names after translation into the five different non-English languages required,9 a task that is a barrier to tools of this sort.
Reference to inert or inactive ingredients
Proposed proprietary names should not include reference to inert or inactive ingredients of a product. Although in the past, such ingredients on occasion affected the bioavailability of the active ingredients, modern standards ensure that this should no longer be a problem.
Combinations of active ingredients
When more than one active ingredient is included in a medicinal product, the proposed proprietary name should not include or suggest the name of any of them, if all of the ingredients are not referred to. In other words, the name might include or suggest the names of all the ingredients or none of them at all. Presumably it is the latter that is generally expected. For example, the MHRA guidance refers to a European Directive (2001/83/EC) that specifies that a proprietary name should not be used if it is likely to be confused with the generic name of the drug that the product contains. That is a useful principle to follow.
United States Adopted Names (USANs)
USANs are the US equivalents of British Approved Names (BANs), i.e. generic names, and therefore proposed proprietary names should not include, in the same position in the name, stems that are used in the formulation of USANs. For example, the suffix –pril is a stem that designates ACE inhibitors such as enalapril and lisinopril, and it would not be acceptable as a suffix in the proprietary name of any medicinal product, whether it contained an ACE inhibitor or not. It could, however, be used in a position in the name other than the suffix.
The guidance points out that occasionally such a use may be unavoidable, for instance in cases in which the stem is also found in an ordinary English word that is relevant to the product. The example given in the document is the infix –gest–, a USAN stem used for progestins, such as megestrol, and it is also found in the word “congestion,” which might be incorporated as part of a proprietary name.
Brand name extensions
This is an American term for what are referred to in the MHRA document as umbrella terms. Both deserve separate consideration at another time.
Re-use of proprietary names
A proprietary name previously but no longer in use for a particular product may not be re-used for a new product with different constituents, because confusion between the discontinued product and the new product is possible.
Use of unpronounceable letters and numbers
This restriction is introduced because proprietary names should be pronounceable as real words, as is also stressed in the MHRA guidance.
A proviso
The FDA’s document is very long, and I have not covered all aspects of it.
My summary of the FDA’s guidance in the sections on what is and is not acceptable in the formulation of proprietary names contains my own interpretation of the guidance and should not be regarded as a definitive version. For that, the original guidance should be consulted.4
Footnotes
Competing interests: JKA chairs The British Pharmacopoeia Commission’s Expert Advisory Group on Pharmacy and Nomenclature and is a member of the WHO’s Expert Advisory Panel on International Pharmacopoeia and Pharmaceutical Preparations.
Provenance: not commissioned; not peer reviewed.