Because of its broad spectrum of action, Levofloxacin is frequently prescribed empirically for a wide range of infections before the specific causal organism is known. Levaquin is generally well tolerated however skin rashes, nausea, and diarrhea have been reported. Diarrhea that usually ends after treatment is a common problem caused by antibiotics. Side effects of Levaquin include tendon ruptures and other tendon type of injuries. Be safe and effective for the treatment of many bacterial infections. Levaquin is concentration-dependent, meaning it kills bacteria most efficiently when the right amount of medicine has been absorbed into your body.