helicobacter pylori infection
"Most horrible side effects: Bitter taste in mouth even hours after administration, balance problems, confusion, surroundings seem unreal, like walking in a dream ( not a good one) concentration problems, general malaise, not able to eat anything but oatmeal and mashed potatoes. Extreme weight loss.  Had to stop after 11 doses. Stomach worse then before.
I have to add that I also had Amoxicillin and Protonix at the same time, maybe the combination was at fault for this extreme reaction."