I am on Levaquin 500, day 12, first 5 days I had stomach gurgles, slight loose bowels, slight dizziness ,facial acne breakout and definite insomnia if taken after 2 pm...last 7 days have been fine. I am 50 years old and had infection after mastectomies. I run 2 miles a day, drink lots of water and am so glad to be rid of the infections. I will go to MD to make sure I don't have a silent yeast infection.