My LLMD just added in Ceftin, which I started on 3/27. I'm also on Zithromax and Septra - just stopped Tindamax and Plaquenil. I'm tolerating it fine as far as my stomach goes, but I have tolerated most of the meds pretty well. I think this is because I'm very careful with my diet - no sugar, processed foods, etc. and take probiotics and nystatin.
I do think the Ceftin may be causing a herx, though, as I started having those intense aches and pains throughout my body (flu-like feeling) about three days after I started it. It's been awhile since I've had this. Hopefully, that's a good thing.