pneumonia
"I've been given this medicine twice - once for serious bronchitis/pneumonia that nearly required hospitialization. Since I am a well trained athlete, hospitalization for a lung infection was serious.  Doctors tried several other drugs before the Levaquin, but Levaquin was best.  Now dealing with a relatively minor bronchitis and have it again.  I've never had any of the side effects others listed - bear in mind that weakness and headaches and many other symptoms might just be the progression of the disease and not due to the drug. It's hard to tell since each bout is different but compared to many other drugs, this is statistically a very good bet.  If you have bronchitis or a respiratory infection, take your medicines with lots of fluids."