Prophylactic efficacy of cephamycin plus fluoroquinolones in high risk patients on inhibiting infectious complications after transrectal prostate biopsy

Brief Communications Many prophylactic antibiotic medications for use during transrectal prostate biopsy (TPBX) have been reported, but most reports did not classify the patients’ risk of infection. Since fluoroquinolones can achieve high concentrations in the prostate they have long been used for prophylactic administration, but recently fluoroquinolone-resistant Escherichia coli (FQRE) has been rapidly increasing. The resistance ratios of E. coli to levofloxacin (LVFX) have also increased from 5 to 20% in Japan in recent years. Extended beta-lactamase (ESBL) producing bacteria, especially Enterobacteriaceae, have become widespread and have been implicated in treatment failure. In updated data, 1.48% of all E. coli in Austria were ESBL-producing. Representative beta-lactamase inhibitors include Tazobactam/piperacillin (TAZ/PIPC), which is often used for urinary tract infection (UTI). To avoid the development of antibiotic-resistant bacterial strains, other narrow spectrum antibiotics are considered to be better for use. Since antibiotic susceptibilities may be different in low risk and high risk patients, selection of prophylactic antibiotic regimens should be based on the risk classifications for infectious complications. Cephamycin [cefmetazole (CMZ)] is known to have a greater effect on gram-negative bacteria and on representative anaerobic bacteria found in human intestine, such as Bacteriodes fragilis, than general cephalosporins. In this study, we focussed on high-risk patients and investigated the effect of CMZ, which generally has good activity against ESBL producing bacteria, plus LVFX, taking risk criteria for infectious complications into consideration, and compared the results for the prevention of febrile infectious complications after TPBX with our previous TAZ/PIPC regimen. We studied 142 consecutive patients with a high risk for infectious complications, who were scheduled for TPBX for suspected prostate cancer. High-risk patients are classified by factors such as severe diabetes mellitus with serum HbA1c level i8.0%, steroids dosing, a larger prostate (i75 mL), residual urine i50 mL, or pre-TPBX bacteriuria. TPBXs were performed at Kobe University Hospital from February 2013 to March 2014. Our previous regimen, TAZ/PIPC, was in use from January 2012 to January 2013. The data were analysed retrospectively. All biopsies were performed as previously described with a modification of 12 [sextant and one each far lateral on both sides from the peripheral zone (PZ) z2 cores each at base and apex on both sides from transitional zone (TZ) cores]. This study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. As a prophylactic antibiotic, each patient received CMZ 2 g i.v. and LVFX 500 mg taken orally 30 minutes prior to TPBX. Patients continued to dose LVFX 500 mg once a day for 3 days in total. The comparative TAZ/PIPC group was given TAZ/ PIPC 4.5 g i.v. 30 minutes before TPBX and continued repeated TAZ/PIPC i.v. 3 hours after TPBX. Patients were examined for febrile infectious complications within 30 days after TPBX. Bacteriological investigations were also performed. White blood cell (WBC) counts (/mm) and C-reactive protein (CRP) (mg/mL) in plasma, pyuria, and bacteriuria (/high power field: hpf) were measured as infection Correspondence to: Katsumi Shigemura, 7-5-1 Kusunoki-Cho, Chuo-Ku, Kobe 650-0017, Japan. Email: yutoshunta@hotmail.co.jp