• The primary efficacy endpoint is clinical success, defined as cured or improved at the Post-therapy Visit, summarized by treatment group. Response is based on the resolution of signs and symptoms at post-therapy. [ Time Frame: Posttherapy Visit (Study Day 33-36) ] [ Designated as safety issue: No ]
  

• Time to symptom relief, relapse rates, and domain scores from the NIH-Chronic Prostatitis Symptom Index and the Daily Symptom Index will be collected during the course of the study and evaluated at study end. [ Time Frame: Poststudy Visits at 6 weeks, 3 months and 6 months ] [ Designated as safety issue: No ]
  

The optimal duration of treatment for chronic prostatitis remains unclear. Historically, therapy for chronic prostatitis with other classes of antibacterials resulted in poor outcomes and prolonged time taking the medication. Levofloxacin belongs to the quinolone class of antibacterials and has been used to treat chronic prostatitis with 500mg of levofloxacin taken orally once a day for 4 weeks. This multicenter, double-blind (neither the patient nor the physician knows whether drug or placebo is being taken, or at what dosage), randomized (patients are assigned different treatments based on chance) study is designed to see if giving levofloxacin at a higher dose for shorter periods of time is safe and effective in treating chronic prostatitis. Safety analyses will involve the examination of the incidence, severity, and type of adverse events and changes in physical findings including vital signs and clinical laboratory tests.

Patients will receive one of the following three dosing options: levofloxacin 750 mg orally administered once-a-day for 2 weeks followed by placebo once-a-day for two weeks for a total of 4 weeks, or levofloxacin 750 mg orally once-a-day for 3 weeks followed by placebo once-a-day for one week for a total of 4 weeks, or levofloxacin 500 mg orally once-a-day for 4 weeks.