Oral fosfomycin for the treatment of chronic bacterial prostatitis

J Antimicrob Chemother. 2019 May 1;74(5):1430-1437. doi: 10.1093/jac/dkz015.


Background: Chronic bacterial prostatitis (CBP) is a difficult-to-treat infection as only a few antibiotics achieve therapeutic concentrations in the prostate. Data on the efficacy and safety of oral fosfomycin for the treatment of CBP are limited.

Objectives: To analyse the efficacy and safety of fosfomycin in CBP due to MDR pathogens.

Methods: In a prospective observational study, an oral regimen of 3 g of fosfomycin q24h for 1 week followed by 3 g q48h for a treatment duration of 6-12 weeks was administered. The outcome was clinical and microbiological cure rate at the end of treatment (EOT) and rate of relapse at 3 and 6 months.

Results: The study included 44 patients. The most common pathogen was Escherichia coli (66%), followed by Klebsiella spp. (14%) and Enterococcus faecalis (14%). Most strains were MDR (59%) and 23% had an ESBL phenotype; 33 of 44 strains were resistant to fluoroquinolones, but all were susceptible to fosfomycin (median MIC for Gram-negative pathogens 1.5 mg/L). In 25 patients, treatment was administered for 6 weeks, whereas in the remaining 19 patients it was prolonged to 12 weeks based on the presence of calcifications in the prostate. Cure rate was 82% at EOT and 80% and 73% at 3 and 6 months accordingly. Microbiological eradication was achieved in 86% and 77% at EOT and at 6 months, respectively. Failure was observed in 12 patients. The most common adverse event was diarrhoea (18%).

Conclusions: Oral fosfomycin, particularly in the era of MDR prevalence, represents an attractive, safe and effective alternative to fluoroquinolones for the treatment of CBP.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Aged
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use*
  • Chronic Disease
  • Drug Resistance, Multiple, Bacterial*
  • Enterococcus faecalis / drug effects
  • Escherichia coli / drug effects
  • Fosfomycin / administration & dosage
  • Fosfomycin / therapeutic use*
  • Humans
  • Klebsiella / drug effects
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Prospective Studies
  • Prostatitis / drug therapy*
  • Prostatitis / microbiology*


  • Anti-Bacterial Agents
  • Fosfomycin