The naming of drugs is not completely a randomised process but depends on various factors most of which are linked to origins, chemistry or any modifications during the drug discovery pipeline although in old times serendipity discovery often led to trivial names being given to drugs.
While morphine seems have been named arbitrarily, the same is not true for its synthetic derivatives . In the opioid class morphine and codeine are considered prototype drugs to which other derivatives are synthesised:
Note: the additional 3-methoxy group gives rise to the -cod- stem name.
e.g. hydromorphone (a synthetic derivative of morphine prepared by the catalytic hydrogenation 7,8 double bond and dehydrogenation of morphine under acidic conditions) hydrocodone (3 methoxy version of hydromorphone) oxycodone (14 beta-hydroxyl version of hydrocodone) and oxymorphone (4 beta-hydroxyl version of hydromorphone, analogous to the hydrocodone, oxycodone pair)
How are drugs named?
Most drugs have at least three different names by which they can be
recognised. These are their chemical, generic (non proprietary) and
trade (proprietary) names. Chemicals names of drugs are extremely
cumbersome to use that they they are almost never used except by
pharmacologists and chemists such a name for example: N-(2,6
dimethylphenyl)-5,6-dihydro-4H-1,3-thiazin-2-amine, which is more
commonly known as xylazine.
Every drug has several different names, and some have a very large number. This abundance of names is often a source of confusion and can indeed be dangerous. The various names have different origins and uses.
To avoid using this, a simplified name method has evolved where
original drug manufacturers together with appropriate drug authorities derive a simplified chemical name from the full name.
The simplified chemical name can mean little with respect of the
chemical name since at times random extraction of pieces of the
chemical name are used to produce a name easier to recall. e.g
Drugs are named in a variety of ways. During the drug’s earliest stages of development, the first name it receives is the chemical name. The chemical name provides scientific and technical information because it is a precise description of the substance in accordance with chemical nomenclature rules established by the International Union of Pure and Applied Chemistry (IUPAC). The chemical name describes the chemical structure of the drug. Because they are long and complex, however, chemical names are rarely used in clinical medicine.
The generic name is commonly used to describe the active drug(s) in the product and is easier to pronounce and remember than the chemical name.
Morphine is derived form the Greek god of sleep, Morpheus (Morphine
was isolated from opium in 1806 by a German pharmacist, Seturner. He
named the compound “morphine” after the Greek god of dreams
On the other hand Salbutamol derived from its chemical name which includes salicyl, butyl, amine and alcohol groups another similar example is acetaminophen or paracetamol.
Other names are derived from the nature of the drug or how it is isolated from the parent substance for example monoclonal antibodies:
because the original monoclonal antibodies (mAbs) were of mouse origin and therefore immunogenic, newer generation mAbs are genetically engineered to modify the mouse regions to appear more “humanized.” mAb nomenclature indicates “-umab” e.g adalimumab as human (produced using transgenic technology), “-ximab” e.g rituximab as chimeric, and “-zumab” e.g alemtuzumab as humanized.
There are precise rules for naming chemical compounds, and the chemical name defines the structure of the drug molecule. Because of this the chemical name of a drug is complex and unsuitable for use inprescribing.
Approved name (or generic)
The approved name is the official name given to the drug. It is usually a short name based on the drug's chemical structure and has the advantage that related drugs have similar names. The approved name is the one which should be used in prescribing.
Proprietary or trade name
The proprietary name is the commercial name given to the drug by the pharmaceutical company which makes and promotes it. Newer drugs are only protected by patent for a few years after their introduction so it is important for the manufacturer to firmly establish the trade name during this period so that when it is out of patent the drug will continue earning revenue. After the patent period runs out, other manufacturers can market the drug and usually introduce new trade names, resulting in the same drug marketed under many different names.
An example case study
The process for naming a marketable drug involves five steps: new chemical entity (NCE) submission and patent application, generic naming, brand naming, FDA review, and final approval.
The U.S Adopted Names Council USAN Council is responsible for creating and assigning generic names to chemicals that appear to have potential as new drugs.
The USAN Council has several criteria for a generic name. The name
must be appropriate for the drug; short, easy to pronounce, and
euphonic; and suitable for routine use both in the United States and
internationally. The name cannot be misleading or confusing or imply
efficacy or application to particular anatomical parts. The name often
has a stem common to related drugs (e.g.,
angiotensin-converting-enzyme inhibitors end in "pril"). The USAN
Council attempts to minimize similarities with other drug names,
Names and classes of drugs. P. Lewis, Essential Clinical Pharmacology. © P. J. Lewis 1981
Veterinary Drug Use, Prescribing, Acquisition, and Pharmacy Management. Brand Name (®) Or Not?
Wilson and Gisvold’s Textbook of Organic Medicinal and Pharmaceutical Chemistry, 12th ed
Naming of drugs: Fundamentals of Pharmacology: Drug nomenclature. Gralbraith et al