EFFICACY AND SAFETY OF DIFFERENT DOSAGES OF FOSFOMYCIN AS ANTIMICROBIAL PROPHYLAXIS IN TRANSRECTAL BIOPSY OF THE PROSTATE
Prostate biopsy, the gold standard diagnostic procedure for prostate cancer diagnosis, is not free from complications, with a post biopsy prostatitis rate ranging between 1 and 5% .
In the recent years, especially in Europe, the incidence of bacterial strains like Escherichia coli, Klebsiella pneumoniae, Enterococci spp resistant to fluoroquinolones and cephalosporine is growing critically, leading to significative death and morbidity risk .
Fosfomicin, a bactericidal antibiotic produced by streptomycetes, shows a good activity against gram positive and gram negative bacteria  and seems to be an attractive alternative to quinolones based prophylactic regimen for prostate biopsies, due to the promising results of Cai et al .
The aim of our randomized study was to evaluate efficacy and safety of a prostate biopsy phrophylaxis protocol using two VS three fosfomicine dosis, with the aim to assess the optimal timing and dosage of this antibiotic.
Materials and Methods
229 patients undergoing transrectal ultrasound guided prostate biopsy were prospectively evaluated between April and December 2016 in a single italian center.
All the patients were evaluated with history, comorbidity evaluation with Charlson score, complete urological examination, PSA, urine exam and urinalysis, transrectal ultrasound.
The patients were, moreover, randomized to group A (fosfomicine 3 gr within 4 hours from the procedure and after 24 hours) and group B (fosfomicine 3 gr 12 hours before the procedure, within 4 hours from the procedure and after 24 hours).
About three weeks after the procedures the patients were evaluated in our outpatients clinic.
229 patients were randomized to group A (n: 115) or group B (n:114); allocation was done by date of birth.
Mean age of the intire cohort was 65 years, whereas more represented Charlson comorbidity index was 0 (49%).
The 2 groups were comparable with respect to age, comorbidity, PSA value, prostate volume, operative time and urine culture results (p n.s.)
23 pts had a positive urine culture, and only one of those > 100.000 UFC; no one was resistant to fosfomicineand only of these (E. Coli plurisesnsible) pts was readmitted after the procedure.
3.4% (8/229) of our patients developed fever requiring a readmission after the procedure (6 in group A and 2 in group B, p n.s.).
Four of these patients presented respectively positive urineculture (only one positive for Enterobacter cloacae resistant to fosfomicine) and two presented a positive hemoculture (only one a Klebsiella pneumoniae resistant to fosfomicine).
None of the patients developed > grade II complications.
Group A (n: 69)
Group B (n: 76)
Age (yrs; mean + SD)
64.9 + 9.1
66.0 + 8.3
65.5 + 8.7
Charlson score (mean + SD)
0.6 + 0.9
0.7 + 1.2
0.7 + 1.1
PSA (mg/dl; mean + SD)
12.4 + 42.1
10.6 + 31.1
Prostate volume (ml; mean + SD)
44.6 + 18.7
49.8 + 26.8
Urine culture > 100.000 UFC
Operative time (min; mean + SD)
12.2 + 7.3
12.2 + 7.9
12.2 + 7.3
Complications (n) (only Clavien I and II)
The low readmission rate of our cohort, treated with both doses of fosfomicine, shows that this prophylaxis is safe and effective.
Moreover, the two doses (2 VS 3 doses) show an overlapping efficacy.
Our study presents, moreover, possible limitations, as the single center, multisurgeon basis and the relatively low number of patients enrolled.
The low fever and prostatitis rate shows that fosfomicine prophylaxis is safe and efficacy; moreover, the two dosage seem to be overlapping in term of post operative outcomes.
1 Linvert K.A., Kabalin J.N., Terris M.K. Bacteremia and bacteriuria after transrectal ultrasound guided prostate biopsy. J Urol. 2000;164:76–80..
2.Taylor S, Margolick J, Abughosh Z, et al.. Ciprofloxacin resistance in the faecal carriage of patients undergoing transrectal ultrasound guided prostate biopsy. BJU Int. 2013 May;111(6):946-53.
3. Hendlin D, Stapley EO, Jackson M, et al. Phosphonomycin, a new antibiotic produced by strains of streptomyces.Science. 1969 Oct 3;166(3901):122-3.
4. Cai T, Gallelli L, Cocci A, et al. Antimicrobial prophylaxis for transrectal ultrasound-guided prostate biopsy: fosfomycin trometamol, an attractive alternative. World J Urol. 2016 May 31. [Epub ahead of print]