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 …