Medicine used for Bronchitis, Pneumonia, and STD's. Among other things.

I can positively say I'm not using this for STDs, but has anyone ever taken this before.
I found it a little odd that they would include on the box that only 1% of people quit using it because of side effects.
Well I can say that I want to be one of those 1%. The abdominal pain and nausea I've been getting for the past two days is almost unbearable. I don't want to puss out because it definitely has helped enormously with my bronchitis. Only three more days to go.

Has anyone had any experience with this? Should I talk to my doctor or just try to tough it out?