The effect of antibiotics on elevated serum prostate specific antigen in patients with urinary symptoms and negative...

65-70% of patients with abnormal prostate specific antigen (PSA) do not have cancer on prostate needle biopsy. Prostate biopsy is a potentially morbid procedure. Prostatitis is commonly reported on needle biopsies. To cut down on the number of unnecessary prostate biopsies we evaluated the effect of antibiotic on PSA level in patients with lower urinary tract symptoms (LUTS), normal digital rectal examination (DRE), normal urinalysis and elevated PSA.

48 selected patients with LUTS, normal DRE, normal urinalysis and elevated PSA (range 5.0-28.5 ng/ml), that usually will undergo prostate biopsy, received 2 weeks of Ciprofloxacin. An alpha-blocker was added if the patient was bothered. PSA was repeated and prostate biopsy was performed if PSA did not drop.

25/48 patients (52%) dropped their PSA (median of 42% drop), with 80% improvement in LUTS, were not biopsied. 23/48 patients (48%) did not drop their PSA, with 65% improvement in LUTS, were biopsied. 9/23 patients (39%) had prostate cancer.

Almost 50% of patients with LUTS, normal DRE and elevated PSA will drop their PSA following 2 weeks of Ciprofloxacin thus by avoiding prostate biopsy. This needs to be done in a very strict manner with careful follow-up of those patients dropping their PSA especially not to normal levels.