treatment requires prolonged courses (4–8 weeks) of antibiotics that penetrate the prostate well (β-lactams and nitrofurantoin are ineffective). these include quinolones (ciprofloxacin, levofloxacin), sulfas (bactrim, septra) and macrolides (erythromycin, clarithromycin). persistent infections may be helped in 80% of patients by the use of alpha blockers (tamsulosin (flomax), alfuzosin), or long term low dose antibiotic therapy. recurrent infections may be caused by inefficient urination (benign prostatic hypertrophy, neurogenic bladder), prostatic stones or a structural abnormality that acts as a reservoir for infection.