The halacha is that you should only say a bracha on water if you're thirsty. All the seforim I've read agree on the following: if you're not thirsty, but you drink water in order to swallow a pill, you don't say any bracha before or after.
Let's say you swallow a pill with Diet Coke or another type of sugar-free pop. But such pop has no nutritional value.
Should you say a bracha on the drink beforehand?
Please cite sources.
I couldn't find an answer to this question online. I seem to recall that The Laws of B'rachos by R' Binyomin Forst (ArtScroll) includes a discussion of when blessings are necessary before food and drink, and when they're unnecessary. But I don't remember exactly what R' Forst wrote.