Hi, Thanks for writing your query. After reading your post, I would like to inform you that Zenflox UTI contains Flavoxate(used for treating frequent, painful urination) as one of its composition which can cause dizziness and drowsiness as side effect. I would advise that you should discuss with your treating doctor with the symptoms you are experiencing and for change of medicine. I would also suggest that you should get your urine examined for Culture and Sensitivity and use the appropriate antibiotic according to the reports. I hope this is helpful to you. Thanks.