Why the same medicine can be called by several different names at your chemist

Explainer - At Clive's Chemist in Wainuiomata, customers know Clive Cannons by name. That's possibly helped by the giant, smiling photo of him pasted to the outside of the store.

This particular Friday afternoon, more than a dozen people were queuing for advice, prescriptions and vaccines next to shelves of Panadol, Codral, Difflam and Flixonase.

They are names we know well, but to get here, scientists had to formulate each medicine in a lab, test it, name it, and then other people had to figure out a target market, a brand name, and get approval to sell it in New Zealand.

What's the difference between branded drugs and those you get on prescription?

Basically, nothing.

We have Pharmac's tendering process to thank for this. In order to get the most bang for buck, Pharmac - a government agency - buys medicines at the best price it can get, and then provides them at a subsidised cost to New Zealanders.

Many companies make similar or identical versions of the same medication. The funded brand changes all the time, depending on which company can give Pharmac the best deal.

Sitting in one of the pharmacy's little consult rooms, Clive Cannons told RNZ they used to arrange their dispensary alphabetically by brand name, but the brand that was funded changed so often they were constantly rearranging. Now, they ordered it by generic name.

Not all patients in need of paracematol came armed with a prescription. That meant unfunded brands still had a market in New Zealand. They sat on the public side of the counter, and attracted buyers with packaging and brand names.

But the drug itself was exactly the same, Cannons said.

In fact, he had recently cut down the number of brands he stocked for common medications. There was no point stocking multiple hayfever medications - for example, Claratyne, Loraclear or LoraFix - when they all contained 10mg of Loratadine.

"It's like a mini Pharmac," he said. "I change it every year, but we stock one brand, because that way we get the best price, we get a bigger discount because we're buying more, and so we can pass that on to our customers."

Generic versus brand names - and where do they come from?

Medicines have two names - generic and brand.

Brand names vary country to country - think Panadol in New Zealand, but Tylenol in the US.

Cannons said at least once a week someone visiting from overseas would come into his chemist and ask, sometimes with a language barrier in play, for a drug he'd never heard of.

Usually, he said, with the help of a picture on a phone, he could piece together what they were after - and it was usually something quite urgent, like blood pressure or diabetes medication.

But a drug's generic name, or INN (International Nonproprietary Name), is unique and consistent worldwide, approved by the World Health Organisation following a set of established conventions - and usually, they're far from memorable.

Daniel Sullivan, general manager of regulatory affairs at Douglas Pharmaceuticals, explained it usually began with the molecule.

Scientists would look at the chemical structure of the medicine they'd developed, and either base the name on that structure, or look to similar products in the market which followed agreed naming conventions.

For example; if it was a beta blocker, the name would likely end in "olol" - propranolol, metoprolol, atenolol. If the drug lowered cholesterol, it would end in "statin" - atorvastatin, fluvastatin, lovastatin.

A number of cancer drugs targeting the immune system end in "mab", which is short for "monoclonal antibodies".

If a medication had two parts to its name, usually the second part indicated the form the chemical came in, Sullivan said.

"So something like metformin hydrochloride as an example. Metformin describes the active part of the molecule that has the therapeutic effect. The hydrochloride in this example is the salt form or the particular version of that molecule that's used to make that particular medicine."

Some forms are easier to make into tablets or injections, and in other cases, it's to get around patent or intellectual property restrictions, he said.

But those names are complex and hard to remember - so companies come up with brand names.

What's in a (brand) name?

Sullivan explained the process of deciding a medication's brand name varied depending on the size of the company. Large multi-nationals might contract it out to a marketing firm, where they would draft 20 names and send them to the company chief executive to shortlist, before sending them off to the country's regulator for approval.

Sometimes it was about standing out. For years, the letter J had been unpopular because it translated into a different sound depending on the language - but now, it was becoming more popular, as a point of difference, Sullivan said.

David Willis, chief executive of Alchemy Health, told RNZ he remembered a time when the naming process was a lot easier.

"There was an explosion in the 1980s and 90s of medicines, compared to the 50s and 60s when there was just a limited number of prescription medicines that doctors could write prescriptions for," he said.

"Back then, it was a piece of cake. Pick a name out of a hat and you could get it trademarked for your own brand."

But come the 90s and early 2000s, he said, big pharma companies were trademarking every possible name, just in case.

Having worked in pharmaceuticals in the UK and then later in New Zealand, Willis said coming up with a brand name often involved weeks of back and forth with lawyers, emailing lists of names for their approval, with most knocked back for being too similar to an existing trademark.

In New Zealand, Medsafe, part of the Ministry of Health, explained that it approved brand names against a number of criteria.

"Medicine names must be clear, unambiguous, not misleading about its purpose or effects, and not likely to be confused with any other medicine in New Zealand," it said.

Sometimes the brand name attempted to invoke images of good health. The case of Viagra was well documented, with the brand intended to resemble words like "vim, vigour, and vitality".

When the usual naming process failed, sometimes a shot in the dark did the trick.

After a month drafting possible brand names for an osteoporosis drug called alendronate, sending them off to the lawyers for approval only to be knocked back every time, Willis said he eventually tried something a bit left-field.

"My daughter's called Rosa," he said. "So I threw it at the lawyers out of frustration - 'for Rosa'. And they came back and said, Forosa, you can have that."

A now popular naming convention began in the early 2000s - "company name-generic name". Putting the company name before the generic name meant it was automatically a name nobody else had. Thus, Arrow-Fluoxetine became Arrow's version of the antidepressant known elsewhere as Prozac.

How did Pharmac change the naming game?

Once upon a time, companies used to pick brand names which were easy for doctors to remember, simply to increase the likelihood that their version of the drug would be used over others.

But Pharmac's tendering system has made that practically redundant for funded products.

Willis explained: "Usually you don't need the doctor to remember a brand name because whatever they write on the prescription, either the old brand name or the generic, there's only one medicine that will be given to the patient - the one that Pharmac pays for."

Back in Clive's Chemist, the customers are backing up. So one last question - had any names stuck with Clive over the years?

Not in particular, he said - but he had recently suggested "Jakavi", a drug used to treat Myelofibrosis, as a potential baby name for an expectant colleague.

So far, it didn't appear they'd taken him up on it.

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