I'm on an extended water-only fast for other reasons, and I began to research the effect of continuing to take herbs and supplements during it. I wanted the benefits of the fast but I could not afford to stop the herbs. Bottom line seems to be that if you need them, you need them, though they might have some attenuating effects on the fast, the fast will still do you a lot of good.
Anyway, I came across this short story of a guy with long Lyme, with years of antibiotic use. The antibiotics helped him only while he was taking them, each time he stopped he would quickly relapse. Finally he tried a fast and had fabulous and permanent results. Might be worth a read.
http://www.smashcompany.com/philosophy/how-i-recovered-from-lyme-disease