I take 300 mg in the morning, and 300 mg at night, on the off days from my IV Rocephin. I never felt like that, and I've had some heavy duty Herxing on Ceftin days,
but I figure that's more likely from the prior day's Flagyl or Rocephin. Ceftin might be more potent at your dosage though.
I never got diarrhea, but I've heard that Rocephin can give you diarrhea, and Ceftin/Omnicef are its closest oral ABX.
When I was on only Ceftin and Bactrim had only mild Herxing once or twice a week, and felt better than before I started ABX most of the time.
Diarrhea could be one of the side effects, but with ABX "side effects" could have side effects because some people were Herxing in the test group.
It could be killing spirochetes in your GI system, or you may be sensitive to antibiotics in general. If it keeps up, I'd talk to your doc.
Post Edited (RobNOrl) : 11/1/2014 7:41:22 PM (GMT-6)