Tuncay Kurt (asker) Jun 4, 2011:

the result I have asked the client about a possible typo and the answer was "surely not"! So I omitted one of them and just used "once daily". As Anton said, eventually I got the idea that "one-a-day" term was a marketing trick. So I preferred just "once daily". The client did not ask for the money back so they must be happy with it. Thank you all! :)

Tony M May 27, 2011:

@ Asker "I came across Once-Daily or Once-a-Day differentiation"

Actually, I'm not sure this is necessarily differentiation — people sometimes express themselves this way when two terms are simply synonyms, and they want to make sure that people familiar with one term but not the other don't get confused.

Anton Konashenok May 27, 2011:

It's a research paper title, isn't it? If so, then it's definitely not "one-a-day", which is consumer marketing speak.

Tony M May 26, 2011:

O-A-D I think you may have a (repeated) typo there, Tuncay.

Of the over a million hits I found on Google, a goodly number confirmed that the acronym O-A-D does indeed stand for 'one-a-day' rather than 'once-a-day'

I think in that case, it is legitimate for the author to have mentioned both terms, even though for the purposes of your translation, I don't think any distinction is likely to be necessary or useful.

Anton Konashenok May 26, 2011:

There is no reason to take tadalafil more than once a day, as it is a long-acting drug: its average elimination half-life is about 17 hours, and a single dose is considered to be effective for 24-36 hours. The reasoning behind administering it once a day, as opposed to on demand only, is most likely a hypothesis that continuous presence of drug in the patient's body may help the patient get erections more frequently than he actually intends to have sex - for example, in the morning; many cases of erectile dysfunction are "trainable" - that is, the more often and the longer the patient has an erection, the better he is able to achieve and sustain one when needed.

Tuncay Kurt (asker) May 26, 2011:

Until now there is no clear distinction between these two but since the topic is on-demand/as needed therapy with this drug I am totally confused about it. He MIGHT mean that patient can take this drug more than once in a single day if "needed"? BUT until now there is no information about this type of usage. Yet, here is another confusing sentence from the text "Why the Once-Daily/Once-a-day (OAD) Alternative to On-Demand Dosing in Erectile Dysfunction (ED)"...I think I will take the risk and ignore one of them and will surely inform the client about this.

medeast May 26, 2011:

I fail to see the distinction between “once-daily” and “once-a-day”. Does the author of the PPT presentation use two terms to avoid repetition? Just a thought. Do you see a difference in meaning in your text?

Damian Hosford May 26, 2011:

Tony M has a point, there are references to both from reliable sources on the Internet too.

Tony M May 26, 2011:

Are you sure about your source text? I can see absolutely no reason whatsoever for differentiating between the two terms as you have posted them.

HOWEVER, if the second term had in fact been 'one-a-day', then I could see why a distinction was being made...