At some point in your life, you will find yourself with a prescription to fill from your doctor. While it is important to keep track of all the medicines you are taking, it can be difficult to do so when the names of many of these drugs are difficult to pronounce and even harder to remember.
In my role as a pharmacist, I have helped countless patients find out which medicines they were taking for which disease. Some wonder why they were prescribed the drug in the first place, or need help distinguishing between drugs that seem completely unexplained.
But there is a rhyme and a reason for the names of drugs. All prescribed medicines follow a standard nomenclature that describes what the drug is made of and how it works.
What are drugs?
Drugs get a brand, or proprietary, name and a generic name that is non-proprietary. Each is assigned to a slightly different process.
Unless a drug compound is trademarked, drug companies assign a proprietary brand name to the drugs they sell. Usually the brand name relates to the conditions the drug is intended to treat and is easy to remember for both providers and patients, but does not follow a standardized nomenclature guideline. For example, the drug Lopressor helps lower blood pressure.
On the other hand, generic drug names all follow a standard nomenclature that helps medical providers and researchers more easily identify and classify the drug. Lopressor, for example, is a generic name for metoprolol tartrate. The US Adopted Names Council, composed of representatives from the Food and Drug Administration, the American Medical Association, the US Pharmacopeia and the American Pharmacist Association, works with the World Health Organization to assign international non-proprietary names, or INNs, to pharmaceutical compounds. Similar organizations exist internationally.
A globally recognized naming process makes the game of an otherwise confusing name much more manageable. It helps the medical community learn and classify newly approved drugs more easily and reduces prescribing errors by providing a unique, standard name that denotes each active ingredient in the drug.
For example, many type 2 diabetes medications fall under a class called glucagon-like peptide-1 (GLP-1) receptor agonists. Although all drugs in this class have different brand names, each generic version ends in the suffix “-tide”. It helps health providers to identify all the drugs that belong to this drug class. Some examples include Byetta (exenatide), Trulicity (dulaglutide) and Victoza (liraglutide).
How are generic drug names specified?
The naming process begins when a pharmaceutical company submits an application to the US Adopted Names Council with a proposed generic name. USAN considers many factors when evaluating a name, such as whether it is related to the way the drug works, how translatable it is to other languages, and whether it is easy to say. In general, the name should be simple — less than four syllables long — and not be easily confused with other existing generic drugs.
Once a name is agreed upon by USAN and the pharmaceutical company, it is proposed to the INN expert group. Sponsored by the World Health Organization, the INN Expert Group is made up of global experts representing the pharmaceutical, chemical, pharmacological and biochemical sciences. They can either accept the proposed name or suggest an alternative. Once the pharmaceutical company, USAN and the INN expert group come to an agreement about a name, it is placed in the WHO Drug Information Journal for four months for public comments or objections before its final adoption.
What is in the name of a generic medicine?
Common names follow a prefix-infix-stem system. The prefix helps to differentiate a drug from other drugs of the same class. The sometimes overused infix, further subclasses medicine. The stem at the end of the name indicates the function of the drug and marks its place within the name game.
Stems are made up of one or two letters that describe the biological effects of a drug as well as its physical and chemical properties and structure. Medicines with the same stem share characteristics such as the conditions they treat and how they work in the body. WHO publishes regularly updated stem books to keep everything in line.
For example, the stem “-prazole” indicates that the drug chemically belongs to a class of compounds called benzimidazoles that perform similar functions. As a result, drugs such as lansoprazole (Prevacid), esomeprazole (Nexium) and omeprazole (Prilosec) treat acid reflux, ulcers, and heartburn. The “E” prefix of esomeprazole distinguishes it from omeprazole, which has a slightly different chemical structure.
Another common example is drugs that use the stem “stat”, which means enzyme inhibitor. Atorvastatin (Lipitor), rosuvastatin (Crestor) and simvastatin (Zocor) are all inhibitors of the same class that block a key enzyme in the body’s cholesterol production process. As a result, these cholesterol-lowering “statins” are used to prevent cardiovascular conditions such as heart disease and stroke.
Are there exceptions to the name game?
Although generic names persist, brand names have undergone several changes over the past few decades following an increase in prescribing and dispensing errors. Some examples include the acid reflux and stomach ulcer drug omeprazole, which was rebranded from Losec to Prilosec because it was often confused with the diuretic Lasix. Another example is when the antidepressant Brintellix was changed to Trintellix because it was commonly confused with the blood thinner Brilinta.
Some generic drugs can work on multiple targets in the body and can be used for many conditions. For example, drugs with the stem “-efil,” such as tadalafil (Cialis), sidenafil (Viagra) and vardenafil (Levitra), belong to a class of drugs that relax smooth muscles and widen blood vessels. Although commonly prescribed for erectile dysfunction, they can also be used to treat pulmonary arterial hypertension, a specific type of elevated blood pressure that affects the arteries in the heart and lungs.
In addition, nomenclature guidelines are not set in stone, and the US Adopted Names Council anticipates that they will continue to change as new, more complex substances are discovered, developed and marketed.
For example, an increase in the number of drugs developed with different salts and esters has led to the use of a modified nomenclature procedure to include the inactive parts of the compound.
As you might guess, it takes health care providers countless months and years to learn and understand this naming process. We are taught the science behind each chemical structure and how it works, which makes it easy to know the rules of the name game. But for those who don’t have a background in chemistry and biology, it can be like reading a foreign language.
However, there are many resources that can help you navigate the drug name game. Ask your health care provider or pharmacist if you have questions about how your medicine works or what it is used for. They usually go by a phone call or away.