Feature Christmas 2010: Reading Between the Lines

A dose by any other name would not sell as sweet

BMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.c6895 (Published 15 December 2010) Cite this as: BMJ 2010;341:c6895
  1. Rob Stepney, freelance medical and science writer
  1. 1Charlbury, Oxfordshire, UK
  1. Correspondence to: walcot2{at}freenetname.co.uk

Inventors of drug names suddenly stood the alphabet on its head. Why did z and x become so attractive in the attempt to influence prescribers? asks Rob Stepney

If you leaf through the June 2000 issue of the British Journal of Cardiology you will see advertisements for Zocor, Xenical, and Cozaar before you reach a brand name that does not contain a prominent x or z (and that brand is Viagra). In an issue of Hospital Doctor from the same month (22 June), adverts for Celebrex, Topamax, Flomax, Vioxx, Zispin, Zyprexa, Oxis, Efexor, and Fosamax outnumber those for brands not containing letters from the tail end of the alphabet. Examination of the British National Formulary (BNF) from 1986 to 2004 confirms that z and x suddenly achieved remarkable and previously unexplained popularity in the branding of drugs.

Of 1436 products added to the BNF between 1986 and 2005, more than a fifth had names that began with z or x or contained a prominent x or z within them. In 1986, only 19 branded drugs began with one of these letters. Over the next two decades, the number of brands beginning with a z increased by more than 400% (to 63) and those beginning with an x increased by 130% (to 16). In the same period, the overall content of the BNF grew by only 80%.

Why did these letters suddenly become so attractive to companies trying to persuade doctors to prescribe their drugs? In linguistics, the “zuh” sound is described as a voiced fricative. The “fricative” element refers to the fact that airflow directed over the tongue becomes turbulent when passing the sharp edges of the teeth, while the “voiced” aspect reflects the vibration of the vocal cords. But there is nothing magical in the sound itself. One suggestion for the popularity of z is that it works well in the Middle East, which was becoming an increasingly important market for drug companies. This has a superficial plausibility: think of how Arab scientists launched astronomy with the terms zenith and azimuth and zodiac. X, though representing the unknown for centuries, has been famously associated with medical advance since x rays. So this too would have appeal.

More likely, though, is that use of these letters relates to the imperative to make a brand name highly visible in a crowd. Reflecting their infrequent occurrence in English words, x and z count for 8 and 10 points in Scrabble, the highest values (along with j and q) in the game. So names that contain them are likely to seem special and be memorable. “If you meet them in running text, they stand out,” is the way one industry insider explained. Generally, they are also easy to pronounce.

That is an old insight in the wider field of marketing. But in pharmaceuticals z did not really take off as a brand initial until after 1996, with the number of drugs beginning with the letter rising steeply from 29 to 51 in 2000 (figure). And the widespread use of x (often also pronounced as “zuh”) is later still. Something additional started the bandwagon rolling.


Fig 1 Number of drugs with a brand name beginning with z or x listed in March edition of BNF for each year. New formulations of existing brands and zinc related compounds have been excluded

Z and x spell Zuxess

Whatever the initial thinking that lay behind the use of the letter, the people responsible for marketing drugs spotted in the 1990s that an unusually large number of z brands had already achieved blockbuster status or were well on the way towards it.

Both Wellcome and Glaxo—then unrelated companies—showed an early liking for z and enjoyed conspicuous success. Wellcome had introduced Zyloric for gout in 1966 and Glaxo the intravenous antibiotic Zinacef in 1978. But it was in 1981 that both companies hit the jackpot with Wellcome’s launch of the antiherpes drug Zovirax and Glaxo’s launch of the H2 receptor antagonist Zantac. In 1985, Zovirax became the world’s first billion dollar drug; and Zantac was the world’s best selling drug by 1986.1 2 In its first 20 years, it was used to treat more than 200 million people.3

The antihistamine Zirtek and the first agonist of luteinising hormone releasing hormone Zoladex (both introduced in 1989), the antibiotic Zithromax (1991), and the proton pump inhibitor Zoton (1994) all became highly successful; and Prozac (1987) made such an impression that its name branded a generation. In 2003, three of the world’s top 10 drugs (each grossing between 3 and 10 billion dollars annually) were Zocor, Zyprexa, and Zoloft.4 Also among the top ten drugs that year were two with the X factor: Nexium and Plavix.

The widespread use of x at the start of a brand is a more recent ploy in drug marketing, seemingly designed to achieve the sound of a z while looking different. In the 1985 BNF there are a few (notably Xanax, Xylocard, and Xyloproct). The big year for brand introductions with this feature did not come until 2002, but by 2005 there were more than a dozen including Xalacom, Xenazine, Xyzal (successor to Zirtek), Xeloda, and Xatral.

People who work in branding speak of it as a means of making a product more than it actually is. In many areas, this is achieved by adding persuasive emotional (and some would say irrational) content. If you buy a car named after an animal famed for its exhilarating speed and elegance, that is what you associate with the vehicle. But in the tightly regulated world of pharmaceuticals, drug names are supposed to be devoid of what the Medicines Control Agency used to call “unsubstantiable beneficial” connotations.

Certain drug names have always alluded helpfully to the chemical class of the agent (as in Innovace, Tritace), its target organ (Pulmicort, Flixonase), the plant species from which the prototype drugs were derived (Taxol, Oncovin) or the drug’s molecular target (Herceptin, Erbitux). Otherwise, when they are sticking to the rules, those inventing brand names for drugs have little scope to play with anything but the sound of letters, and to some extent the appearance of the word. This is presumably why we have the odd repetitions seen in Vioxx and Cozaar) If any alphabetical quirk seems to be working well, there must be a strong temptation to follow suit.

Sometimes, though, the rules get bent or broken. Aprovel manages to convey the idea of endorsement and Celebrex and Zestril a clear joie de vivre. Indeed, the contrasting stories of the two brands of lisinopril, both launched in the late 1980s, would make an interesting case study. ICI Pharmaceuticals called its lisinopril Zestril. Its competitors marketed the same molecule as Carace. Whereas Zestril became one of the medical world’s most successful brands, Carace sank pretty much without trace. Was the difference due to the z, the zest, or both?

Product naming, of course, is an art that extends across all commercial activity; and z and x have played an important role elsewhere. Of the 10 cars currently listed as fastest in the world (all capable of 0-60 mph in under four seconds), four—including the Ferrari Enzo and the Jaguar XJ220—have a z or x in their names.5 For some brands, the prominence of a key letter is fortuitous: Zanussi, the white goods manufacturer, apparently derived its name from the early 20th century blacksmith and stove manufacturer Antonio Zanussi. But there are many examples of brand name coinage that are as contrived as those used to market drugs and precede them. For the best part of a century, marketing has gone for certain arbitrary syllables like “ex”, “ax” or “ox”. These are stuck on to a meaningful word, as in Timex, Artex, or Tampax, or a meaningful word misspelt, as in Kleenex (introduced in 1924). Xerox, which became a trademark in 1948 (50 years before the double x stratagem became popular for drugs) is an acknowledged classic.

That said, the use of x and z in drug brands suddenly became extraordinarily prevalent. I suggest that this phenomenon arose because of the fast rate at which new products were being introduced, the fact that the difference between many “me too” drugs was more apparent than real, the immense rewards that were seen to accrue from innovative marketing, and the fact that the ploys available for use in the naming of drugs are so restricted.

Generic names of drugs listed in the article

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Cite this as: BMJ 2010;341:c6895


  • I thank the staff of the BMA library for their help in enabling me to consult copies of the British National Formulary from 1985 to 2005.

  • Competing interests: The author has completed the unified competing interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declares no support from any organisation for the submitted work; no financial relationships with any organisation that might have an interest in the submitted work in the previous three years; and no other relationships or activities that could appear to have influenced the submitted work.

  • Provenance and peer review: Not commissioned; externally peer reviewed.