What antibiotics are recommended for prophylaxis in prostate biopsy?

Antibiotic Prophylaxis for Prostate Biopsy

For transrectal prostate biopsy, the recommended antibiotic prophylaxis should be targeted based on rectal swab culture when possible, or include alternative antibiotics such as fosfomycin trometamol, cephalosporins, or aminoglycosides when targeted prophylaxis is not feasible. 1

First-Line Recommendations

• Targeted prophylaxis based on rectal swab or stool culture is the preferred approach, as it reduces the risk of post-biopsy infection by 5.6-fold compared to empirical prophylaxis 2
• When targeted prophylaxis is not possible, the following alternatives are recommended:
  • Fosfomycin trometamol (3g before and 3g 24-48 hours after biopsy) 1, 3
  • Cephalosporins (e.g., ceftriaxone 1g intramuscularly or cefixime 400mg orally for 3 days starting 24 hours before biopsy) 1
  • Aminoglycosides (e.g., gentamicin 3mg/kg intravenously or amikacin 15mg/kg intramuscularly) 1

Evidence Supporting Recommendations

• The European Association of Urology (EAU) 2024 guidelines explicitly recommend targeted prophylaxis as the first choice for transrectal prostate biopsy 1
• Historically, ciprofloxacin was the standard prophylactic antibiotic for prostate biopsy 1, 4, but increasing fluoroquinolone resistance (up to 57% in some studies) has necessitated alternative approaches 2
• A systematic review and meta-analysis found that fosfomycin trometamol is an effective alternative to fluoroquinolones with reduced rates of infectious complications (RR 0.49,95% CI 0.27-0.87) 5

Duration of Prophylaxis

• For fluoroquinolones (where still permitted), a minimum of a full 1-day administration is superior to single-dose prophylaxis 5
• For fosfomycin trometamol, a two-dose regimen (pre-biopsy and 24-48 hours post-biopsy) is recommended 1, 3
• For cephalosporins, either single-dose parenteral (ceftriaxone) or multi-day oral regimens (cefixime) are options 1

Special Considerations

• Augmented prophylaxis (using multiple rather than single antibiotics) may be considered in high-risk patients, though this approach contravenes antibiotic stewardship principles 1
• Local antibiograms should be consulted when selecting empiric prophylaxis due to significant regional variations in bacterial resistance patterns 6
• The indication for fosfomycin trometamol for prostate biopsy has been withdrawn in some countries (e.g., Germany), so clinicians should check local guidance 1

Pitfalls to Avoid

• Relying solely on fluoroquinolones without knowledge of local resistance patterns may lead to treatment failure and serious infectious complications 2, 6
• Using single-dose prophylaxis when longer duration has been shown to be more effective 5
• Failing to consider patient-specific risk factors for infection, such as prior fluoroquinolone use, recent hospitalization, or international travel to areas with high antibiotic resistance 2, 5
• Neglecting to obtain rectal swabs before biopsy when targeted prophylaxis is feasible 2

Algorithm for Antibiotic Selection

1. Obtain rectal swab for culture 1-2 weeks before scheduled biopsy 2
2. If rectal swab shows susceptible organisms:
   • Provide targeted antibiotic based on susceptibility results 1
3. If rectal swab shows resistant organisms or targeted prophylaxis is not feasible:
   • Fosfomycin trometamol (3g before and 3g 24-48h after biopsy) 1, 3
   • OR Cephalosporin (ceftriaxone 1g IM or cefixime 400mg PO for 3 days) 1
   • OR Aminoglycoside (gentamicin 3mg/kg IV or amikacin 15mg/kg IM) 1
4. For high-risk patients with multiple risk factors, consider augmented prophylaxis with two antibiotic classes, despite stewardship concerns 1, 7