Antibiotic prophylaxis for transrectal prostate biopsy.

Abstract

Prostate cancer is the second most common cause of cancer death in men in the United Kingdom. 1 Transrectal ultrasound (TRUS), digital rectal examination and assay of prostate-specific antigen (PSA) are used in the diagnostic assessment. It is established practice to perform TRUSguided prostate biopsy in patients with palpably and ultrasonically abnormal prostate glands. 1 However, 25% of early prostate cancers are not visible on ultrasound and it is generally accepted that multiple biopsies should be performed systematically in patients with palpably and ultrasonically normal prostates and a serum (PSA) level greater than 10 ng/mL. 1,2 Several studies have shown that, in patients undergoing transrectal prostate biopsy, administration of prophylactic antibiotics results in a lower incidence of post-biopsy febrile episodes, 3‐5 positive urine cultures and bacteraemia. 3‐8 However, little consensus exists as to the most appropriate antibiotic regimen. In a recent survey of 106 radiology and urology departments, we found a total of 48 different regimens utilizing 13 antibiotics. Metronidazole (administered po or pr) was the most commonly used antibiotic, featuring in 55% of regimens, followed by oral ciprofloxacin in 48% of regimens. Gentamicin (iv) was used in 48% of regimens and oral trimethoprim in 14%. Most regimens (89.7%) utilized an oral antibiotic. Of the regimens, 58.6% included an intravenous antibiotic and 29.3% combined intravenous, oral and rectally administered antibiotics; 29.3% of regimens consisted of oral antibiotics alone. Few prospective studies have addressed the issues of antibiotic type, dose, route of administration, duration of treatment and cost in prophylaxis of transrectal prostatic biopsy. The efficacy of oral ciprofloxacin compared with intravenous gentamicin as prophylaxis against bacteraemia after transrectal prostate biopsy has been demonstrated. 9 Patients received either 500 mg ciprofloxacin 12 h before biopsy and 12 h later or 1.5 mg/kg gentamicin intravenously 2 h before biopsy and 80 mg 8 h later. Of the patients who received gentamicin, 37% had bacteraemia after biopsy compared with 7% of those in the ciprofloxacin group. None of the patients given ciprofloxacin developed clinical signs of bacteraemia whereas six of those in the gentamicin group did. The authors concluded that the advantage of ciprofloxacin as prophylaxis against bacteraemia might be due to the drug’s known ability to concentrate in the prostate gland. The authors recommended ciprofloxacin as prophylaxis because, compared with gentamicin, it is less nephrotoxic and ototoxic, less expensive and can be administered orally. 9 In a recent review of the fluoroquinolones 10 the question of their efficacy as prophylaxis in transrectal prostate biopsy was not addressed specifically but the author did recommend that a quinolone be used as first-line therapy in patients with complicated Gram-negative urinary tract infections. In this setting, norfloxacin is cheaper than ciprofloxacin and may be as effective. 10