Herxheimer symptoms, is this common?

I used to have a little arthritis but got my inflammation down and it disappeared.  Now that I started MMS protocol 1000 it's back!  What the heck.  I read testimonials that it makes arthritis disappear.   I feel my inflammation is back?  Is that normal?
I don't want to stop taking it but it also makes my throat burn horrible and it makes me feel dehydrated.  I have upped my water intake but still feel dehydrated. 
On MMS 1000 and FENBEN for breast cancer.