Talk to your healthcare provider about the precautions and warnings with levofloxacin to help ensure safe use of the drug. Do not exercise until your healthcare provider makes sure you do not have a ruptured tendon. This problem can occur while you are taking the medication or even months later. This severe reaction can occur long after you stop taking levofloxacin and can be life-threatening. 2  Levofloxacin can cause nerve problems. 3  Be sure to tell your healthcare provider if you develop any unusual sensations (such as numbness, burning, or tingling) while taking levofloxacin.