I have not had any adverse reactions to Levaquin. After age 30 I suddenly became allergic to penicillan AND erythromycin,clarithromycin,azithromycin-- making prescribing antibiotics very difficult, especially since I was already allergic to sulfa drugs, too. I have taken Levaquin approx 5 times for various upper-respiratory infections, ear infections, etc---works great, but very expensive.