I had a UTI. I m allergic to penicillan. After a 4-day course of Cipro, I realized that the Cipro was responsible for my nausea, dizziness, malaise and heightened hypomania. My doctor s office switched me to sulfamethoxazone. After three days on that, again the same reaction. Since I ve been on an antibiotic for 7 days, can I safely stop? The side effects are getting hard to tolerate. My blood has tested repeated reactive for hepatitis B core antibody. Does this have anything to do with inability to tolerate some antibiotics?