I’ve long wondered why generic drug names (and some brand names) are so complex and hard to pronounce. I’m always impressed when the pronunciation rolls off a doctor’s or pharmacist’s tongue. How do these drugs get their complex generic names, and how do they get their brand names?

Drugs have (at least) two names: a generic and a brand name. For example, acetaminophen is the generic name for Tylenol, ibuprofen is the generic for Advil, sertraline is generic for the depression drug Zoloft, and apixaban is generic for the blood-thinner Eliquis. How drugs get their names is pretty interesting. I’ll first hit the naming of the generic and then how they get their brand names.

Generic Names

In the early stages of its development, a drug is assigned a number by the company developing it. For example, the Pfizer drug CIBINQO (generic name abrocitinib), which treats dermatitis, started its life as PF-04965842.

Once a drug shows enough promise that it is headed for clinical trials, it is given its generic name. Two different organizations must approve the names of generic drugs— the United States Adopted Names (USAN) Council and the World Health Organization (WHO) INN Programme. By having both organizations approve names, health officials worldwide can be sure they are communicating about the same drug.

Generic names are somewhat based on a formula as follows:

The suffix tells the “family name,” which signals how the drug works. Here’s a cheat sheet of suffixes and what they mean:

The prefix is less formulaic and more creative. But there are rules for those as well (source):

• It must use two syllables in the prefix. This will help distinguish the drug from others, and allows for more variety.
• It must avoid certain letters. The generic drug name is created using the Roman alphabet, and the goal is to create a name that can be communicated globally. Because the letters Y, H, K, J, and W aren’t used in certain languages that use the Roman alphabet, they aren’t used in the creation of the prefix of the name.
• It can’t be considered marketing. Using the company’s name within the drug’s name must be avoided. Also, it’s important to stay away from superlatives or laudatory terms (best, new, fastest, strongest) that could be considered promotional.
• It avoids medical terminology. You don’t want to imply that a drug is intended only for one particular function, because in time, if it is also helpful for another purpose, the name could be reductive. Say you were developing a treatment for oncology indications and you launched a product for those  indications, but over time in further research you discovered  it worked on inflammation and immunology indications. If you had something like “Onc-” in the beginning of your generic name that would be very limiting.

Once the generic name has been approved, the branded name is determined.

Branded Drug Names

Brand names aren’t tied to particular suffixes and thus are more creative. The brand name is important for the marketing of the drug and also has an effect on how well the branded drug will continue to sell when its patent expires and it must compete against generics.

The drug company often wants to come up with a brand name that is representative of the drug in some way or conveys imagery or association. For example, with respect to a few Pfizer drugs, “Lyrica, which is used to treat nerve and muscle pain and calls to mind lyrics or music. Viagra, used to treat erectile dysfunction, elicits vitality and vigor. IBRANCE, a breast cancer treatment summons inspiration, embrace, vibrancy.” Source. Some drug names, like Prozac, are unrelated to anything but just stick in our heads (which means it’s a good name).

There are a few rules for brand names. First, they can’t contain any of the suffixes that are used for generic names. Next, the drug name can’t be too fanciful or be the sort of word that would overstate the drug’s effectiveness; it can’t be an overly promotional name. For example, I wouldn’t think the name “Sequoia” would be approved as the name for an erectile dysfunction drug.

Drug companies start with hundreds or thousands of possible names and winnow them down to a few. Sometimes, drugs are marketed under different brand names in different countries due to cultural differences.

With both generic and brand names, safety is the top concern. Drug names need to sound different so there aren’t mix-ups. “For example, FDA examiners are known to look at handwritten samples of a drug name and listen as a variety of people (each with different accents) pronounce the name. They also check for illegal stems, similarity to the names of discontinued products, and common medical or coined abbreviations tucked within the name.” Source