This medication may rarely cause tendon damage (such as tendonitis, tendon rupture) during or after treatment. Your risk for tendon problems is greater if you are over 60 years of age, if you are taking corticosteroids (such as prednisone), or if you have a kidney, heart, or lung transplant. Stop exercising, rest, and get medical help right away if you develop joint/muscle/tendon pain or swelling Ofloxacin should not be used by patients with myasthenia gravis. It may cause the condition to become worse. Get medical help right away if you develop muscle weakness or trouble breathing.