27 Apr 2018
Norman Yarvin

Rifampin and food


I recently went back on rifampin, after having been off it for a while due to liver function test issues. The instructions for rifampin are to take it on an empty stomach; but being the lazy guy that I am, I decided to test whether I could get away with taking it with a breakfast of cereal and skim milk.


Thanks for the detail and the analysis, Norman. It's good to know there's some flex in this. I would have inaccurately misread the 25% reduction AUC as a straightforward one quarter reduction. So it's a boon to have someone around who can, literally, do the math. Keep us posted on how the Rifampin goes for you.

The 25% reduction in AUC basically is a straightforward one-quarter reduction. It's not good, but that's the worst number reported. (It's the reduction in Cmax which is more ambiguous in its impact.) From the strong language in the warnings I'd seen, I'd figured they must be talking about a 50% or 75% reduction in AUC, at least; they made it sound like if you'd eaten, you might as well not even bother taking the stuff. With a possible 25% loss, it's still worth avoiding food, all other things being equal; but they often aren't equal. Going hungry imposes its own stresses on the body, which also are worth avoiding; so this is a tradeoff.

Thanks Norman the antacid information is particularly valuable to me as that is the main issue I have had with Rifampicin.

Michèle (UK) GFA: Wheldon CAP 1st May 2006. Daily Doxy, Azi MWF, metro pulse.