The Y to Z’s of drug names

Rosuvastatin. Pantoprazole. Perindopril. Sertraline. These were some of the most commonly prescribed PBS drugs in 2024. But what else do they have in common?

Tongue-twisters aside, they’re all examples of judiciously crafted drug names that have gone through countless rounds of testing by researchers, developers and brand marketing teams before making their way into Australian pharmacies.

Pharmacists are trained to interpret the class of drugs from the last few letters of a generic name, particularly after Australia transitioned to active ingredient prescribing in 2021. But how do we get from sertraline to Zoloft, and what about the many forms of ethinylestradiol-based birth contraceptives (Yaz, Jolessa… Sronyx)? As it turns out, drug naming is more complex than it seems. 

Australian Pharmacist looks at the hard and fast rules governing drug monikers – all designed with patient safety in mind.

Breaking down a drug name

Pharmacists are likely well aware of the multiple guises medications take – three in fact: their chemical name, generic name (or nonproprietary), and brand name.

The chemical name follows rules set by the International Union of Pure and Applied Chemistry (IUPAC).

Once the drug is approved by the relevant regulator, it’s then assigned a generic and brand name. The generic name is based on the active ingredient and follows a standardised nomenclature, while the brand name is the trademarked name proposed by the manufacturer. 

It’s within these last two categories that drug developers have a bit of scope for creativity.

The science behind generic names

Before paracetamol lands in the pharmacy aisle as Panadol, pharmaceutical companies must first propose a generic name for the medication. 

This name must be greenlit by two organisations: the national regulating body (i.e. in Australia, the Therapeutic Goods Association), and on a global stage, the World Health Organization’s (WHO) International Nonproprietary Name (INN) Programme. 

Generic names follow an internationally recognised formula of prefix–infix–stem to maintain consistency regardless of where someone is located, and minimise the risk of prescribing errors. The:

• stem indicates how the drug functions
• prefix differentiates it from other drugs of the same type
• infix further subclassifies the drug (though is less commonly used).

The table below provides a snapshot of INN-approved stems. 

Source: WHO INN, Drugs.com

While many of these generic names may be a familiar sight on pharmacy shelves, you may be surprised about the naming parameters. 

According to INN’s principles, generic names cannot explicitly convey an ‘anatomical, physiological, pathological or therapeutic suggestion’ to a patient (which could cause confusion if the drug is used to treat multiple conditions). They must translate cross-culturally, avoiding letters such as ‘h’ and ‘k’ which are absent in some Roman alphabetical systems. 

Proposed generic names also cannot be confused with existing drug names to mitigate patient harm through look-alike, sound-alike drug mix-ups; think opioid pain medication tramadol vs tapentadol.

Pharmaceutical companies have a little more wiggle room with the prefix. For example, the anticoagulant warfarin derives its prefix as an acronym of the Wisconsin Alumni Research Foundation (WARF), which supported the research leading to the drug’s development.    

How about brand names?

If you were a pharmaceutical developer at Pfizer, how would you go about naming your new drug? Chances are, you’d begin brainstorming years before your patent application goes through.

Brand names boast one of the more difficult bars to clear, and must be approved by all three global players – the US Food and Drug Administration (FDA), the European Medicines Agency and Health Canada – before it can enter the market. In addition, they must satisfy tricky trademark registrations.

Just like generic names, brand names must adhere to strict guidelines to reduce errors in prescribing, dispensing and patient use. These include:

• Avoiding names that suggest anything offensive, inappropriate or misleading in any of the markets it will be sold.
• Ensuring clarity across different cultures and languages.
• Steering clear of similarities from other generic and/or brand names in use.
• Avoiding overly promotional claims of a drug’s function or effectiveness. For example, the FDA rejected the name NovoRapid for the insulin currently known as Novolog in the US, but the drug is sold as NovoRapid in UK markets.
• Managing situations where a drug must have different names across different jurisdictions. For instance, antipsychotic medicine brexpiprazole is marketed in the US as Rexulti, but is sold under the name Rxulti in Europe. 

Because of their globalised nature and tightening regulatory net, much of the brand naming process has been outsourced to specialised creative agencies. 

Scott Piergrossi, President of Creative at the Brand Institute – a firm which holds the bulk of the market share in FDA-approved drug names – told Forward, agencies will often propose a thousand or so names in the first round, before the list is whittled down to a handful for submission. 

Decoding drug names

There are a few tested strategies for brand drug naming to not only meet the necessary patient safety checks, but also up its chances of becoming a household name, according to pharmaceutical brand consultants.   

It should be easy to pronounce, ideally five to nine letters with two to four syllables. Certain letters like, ‘y’, ‘v’ and ‘z’ are in hot demand because they convey a high-tech, futuristic spin (Xanax, Zepbound). One brand director told the Washington Post companies might lean into an ‘o’ for an oral drug, or use an ‘x’ if the product is developed with an extra level of efficacy. 

Piergrossi, telling Global Health Now, says the perfect name is a blank canvas. Drug name developers might completely make up a word, known as an ‘empty vessel’ (for example, HyQvi to treat primary immunodeficiency). One of the most famous empty vessels was the antidepressant Prozac – it had no prior relation to antidepressants, yet became a shorthand for all when it burst onto the scene in 1988.

Or, companies might embed memorable, psychological associations in the drug about what it does. For instance, Lopressor lowers blood pressure; Imrest is a short-term treatment for insomnia; the discontinued brand name erectile dysfunction drug Levitra calls to mind ‘levitate’. 

The more subtle brand names use every letter to their advantage. Hemlibra, approved to reduce bleeding in patients with haemophilia A, combines the prefix ‘hem’ (from haemophilia), with libra, an astrological sign represented by the scales of balance.