From a clinical trial synopsis (Boehringer Ingelheim 1239.1):

Dose: Starting dose of 150 mg b.i.d. (twice daily) BIBF 1120, followed by dose escalation of 50 mg for successive cohorts, up to a maximum of 250 mg b.i.d. (concomitant with BIBW 2992)

BIBF 1120 and BIBW 2992 are names of drugs. Is the word "concomitant" felicitous here, or is it better to use simultaneously with? What other naturally-sounding alternatives could there be?

I thought that we use "concomitant" when something happens by itself, but here the study authors chose to use this combination of drugs.

2 Answers 2



has a specific clinical meaning which goes beyond "simultaneously", it means two things have a relationship with each other, it can be used for application as well as observed related side-effects.

In your example BIBF 1120 and BIBW 2992 are both kinase inhibitors and so both are meant to be applied together (interrelated) in order to shutdown that biological pathway necessary for angiogenesis.

  • So the authors went for this word with this specific meaning in mind? Thank you. I thought that maybe they chose it because they were not native speakers of English. Dec 29, 2016 at 15:09

If you just want to mean simultaneously with, and there are no other connections between BIBF 1120 and BIBW 2992, concomitant is not the right word.

The Cambridge dictionary provides this definition of Concomitant: note the words that I have highlighted.

something that happens with something else and is connected with it

So, while it is legitimate to say

dementia is concomitant with old age

It is not OK to say

We drank the wine concomitantly with dinner

... unless you really believe that there could be no dinner without wine :-)

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .