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Unspeakable Drug Names


Capecitabine (C15H22FN3O6) is an oncologically important chemotherapeutic prodrug. It has a trade name: Xeloda (pronounced zee-ló-da, I presume). And it’s just as well, because capecitabine is a train wreck of a name.

The normal principles for interpreting English orthography come nowhere near determining even an approximate pronunciation. Try saying capecitabine aloud before you read on. How would you pronounce it, for example, in a lecture? Do you dare to even hazard a guess? The word could be either tetrasyllabic or pentasyllabic, depending on what you assume about the vowels. And among the pronunciation decisions to be made are these:

  • The first syllable could be pronounced as either cap (as in capital or capelin) or if the following letter is silent e, cape (as in capon or caper).

  • If the choice made for the first syllable is cap, then the e that follows it could stand for either the unstressed central vowel called schwa (IPA [ə], like the underlined e incafeteria), or the diphthong of café ([eɪ]), or the open-mid front vowel of pectoral([ɛ]), or the close front vowel of species ([i]).

  • The syllable after that, spelled -cit-, could be pronounced with either a short vowel ([ɪ], as in city) or a long diphthong ([aɪ], as in citation); or possibly the i could represent the long vowel [i:] of machine or marine.

  • The syllable corresponding to -tab- could be pronounced with either [eɪ] as in tableor [æ] as in tabular or schwa as in suitable.

  • And in the final syllable, assuming the final e is silent, -ine could be pronounced as in either marine (with [i:]) or combine (with [aɪ]).

  • And there’s the prosody: The main word stress in a four-syllable or five-syllable word may be on the first syllable, as in cápitalizing, or on the second, as in compénsatory, or on the third, as in paracétamol, or on the fourth, as in peritonítis, or on the fifth, as in superguarantée. Where the stress could be in capecitabine will depend on the vowel choices: one restriction is that schwa never bears stress.

Multiplying out the possibilities, it would be possible to enumerate all the conceivably legal pronunciations, though it would be quite complicated because there are phonotactic and prosodic restrictions to take account of. I haven’t undertaken the task (I encourage commenters to take it on), but preliminary figuring suggests the number is in the dozens, at the very least. And that’s if we posit no one-off irregularities, and also rule out foreign pronunciations – like the perfectly plausible hexasyllabic, penultimately stressed Italianate pronunciation ka-peh-chee-tah-bí-nay (IPA [ˌkapeʧitaˈbine]).

When you’ve decided what your best guess would be out of the many possible pronunciations, then given a basic understanding of the International Phonetic Alphabetyou’ll be able to check your guess against the pronunciation given in the Wikipedia entryfor capecitabine. Interestingly, Wikipedia gives a pronunciation that I never even considered when I was trying to decide what my own choice would be.

And to complicate things even further, I note that the only cancer specialist I am personally acquainted with, a University of Edinburgh colleague, uses a pronunciation that disagrees with Wikipedia and is impossible according to my analysis above (he uses the cap pronunciation of the first syllable but then ignores the first e entirely, skipping a syllable).

For conversational purposes I decided to part part company with Wikipedia and use my specialist acquaintance as the authority when talking to him. He, after all, is not only a member of my speech community who employs the word, but also a medical authority.Sociolinguistic theory would predict that I would use him as a model to emulate, and that’s what I did.

This topic might seem to be nothing more than a harmless curiosity illustrating (once again) the defects of the disastrous writing system under which English labors (it’s undoubtedly among the Top 5 World’s Worst Writing Systems). But I think the issue is actually a bit more significant. Once, when picking up some prescription painkillers, I glanced at the little box inside the paper bag that the pharmacist handed me and found that the drug supplied was completely wrong: It was an unrelated substance that happened to have a name beginning with the same two or three letters. That sort of mistake can kill people. And I suggest (it’s an empirical hypothesis) that such errors will be much more likely to occur if pharmacists are dealing in drugs with names that no one knows how to pronounce.

C… a… p… Ah, that must be the one.

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