It has always created a herx in the form of a bad cold: coughing, sneezing, tearing through thousands of kleenex.

Now that I've been on it a while, maybe there are two things to watch out for--and again, this is just one person's experience.

First, you could ensure that you are getting rid of yeast. I take nystatin and coptis, others take diflucan. There's probably some other stuff out there, too.

Second, you could make sure you don't have co-infections. Ketek really turned my life upside down six months ago, because it helped to reduce the Lyme so effectively (when paired with omnicef) that every remaining symptom fell neatly into a co-infection category. So I also felt sicker than ever, but it was because I wasn't taking the right antibiotic treatment for what I actually had.

Tired, but not sleeping.

Ketek also made me very tired at first. I started splitting the dose between morning and evening, and was less tired. Then it started giving me insomnia, so I now take it all in the morning.

I'd say that it took a good 6 weeks before I could definitely say (after a herx) that yes, I do feel better. Its just hard to tell sometimes. It all happens so slowly.

Yeast-I had no problems with thrush until ketek now I need mycolex (antifungal )troches. Yes, i take high quality probiotics, in the pm.

i was tested and treated for co-infections prior to starting ketek.

It seems I am still herxing on it , at times. do have good days. Lots of achiness/soreness , upper body that I didn't have before. some headaches-LLMD said headaches probably from ketek not herx.

Other than the aches and pains, I seem to be okay.