Trial Comparing a Combined Regimen of Amikacin and Ciprofloxacin to Ciprofloxacin Alone as Transrectal Prostate Biopsy Prophylaxis in the Era of High Fluoroquinolone-Resistant Rectal Flora

BACKGROUND: To investigate whether addition of amikacin to fluoroquinolone (FQ) antimicrobial prophylaxis reduces infections after transrectal ultrasound-guided prostate biopsy (TRUSPB). METHODS: A total of 503 patients undergoing rectal swab were divided into three groups. Patients with FQ-sensitive rectal flora (group 1, n = 248) were administered ciprofloxacin before TRUSPB, and patients with FQ-resistant rectal flora were either administered ciprofloxacin (group 2, n = 97) or amikacin and ciprofloxacin (group 3, n = 158) before TRUSPB. RESULTS: Based on the rectal swab, FQ resistance was 54.9%, and extended-spectrum β-lactamase (ESBL) positivity was 17.2%. The incidence of infectious complication in group 1 was 1.6%. Groups 2 and 3, with FQ-resistant rectal flora, tended to have increased infectious complications (5.2% and 4.4%, respectively) but the difference between those results is not statistically significant. The most common pathogens of infectious complications in patients with FQ-resistant rectal flora were FQ-resistant and ESBL-producing Escherichia coli. E. coli pathogens isolated in Group 3 were amikacin-susceptible species. The operation history and ESBL positivity of rectal flora increased the incidence of infectious complications (odds ratio [OR] = 3.68; P = 0.035 and OR = 4.02; P = 0.008, respectively). DM and antibiotics exposure were risk factors for FQ resistance (OR = 2.19; P = 0.002) and ESBL positivity of rectal flora (OR = 2.96; P = 0.005), respectively. CONCLUSION: Addition of amikacin to ciprofloxacin prophylaxis could not reduce infectious complications in patients with FQ-resistant rectal flora. Despite the amikacin sensitivity of infectious complications, single-dose amikacin addition to ciprofloxacin prophylaxis has limitations.