Is fosfomycin (Fosfomycin) suitable for treating a urinary tract infection (UTI) in a male with a chronic indwelling Foley catheter?

Fosfomycin is NOT Recommended for UTI in Males with Chronic Foley Catheters

Fosfomycin should not be used for treating UTI in a male with a chronic indwelling Foley catheter, as this represents a complicated catheter-associated UTI (CA-UTI) requiring broader-spectrum parenteral therapy, and fosfomycin lacks guideline support or adequate evidence for this specific indication.

Why Fosfomycin is Inappropriate in This Context

This is a Complicated CA-UTI Requiring Different Management

• Males with indwelling catheters have complicated UTIs by definition, which require different antimicrobial approaches than uncomplicated infections 1
• The 2024 European Association of Urology guidelines classify UTI in males and presence of foreign bodies (catheters) as factors defining complicated UTI 1
• CA-UTIs have a broader microbial spectrum including E. coli, Proteus, Klebsiella, Pseudomonas, Serratia, and Enterococcus species, with higher rates of antimicrobial resistance 1

Guideline-Recommended Treatment for CA-UTI

For complicated UTIs with systemic symptoms, guidelines strongly recommend:

• Combination therapy with amoxicillin plus aminoglycoside, OR
• Second-generation cephalosporin plus aminoglycoside, OR
• Intravenous third-generation cephalosporin 1

For CA-UTI specifically:

• Treatment duration should be 7 days for prompt symptom resolution or 10-14 days for delayed response 1
• In males, 14 days is recommended when prostatitis cannot be excluded 1
• Fluoroquinolones (levofloxacin or ciprofloxacin) are options only if local resistance is <10% and the patient has not used fluoroquinolones in the last 6 months 1

Critical Catheter Management Steps

Before starting antibiotics:

• Replace the catheter if it has been in place ≥2 weeks to hasten symptom resolution and reduce recurrence risk 1, 2
• Obtain urine culture from the freshly placed catheter before initiating therapy, as biofilm on old catheters may not reflect bladder infection accurately 1, 2

Why Fosfomycin Evidence Doesn't Apply Here

• Fosfomycin is FDA-approved only for uncomplicated lower UTI in women 3
• Available studies on fosfomycin for complicated UTI are retrospective case series with small numbers of catheterized patients 4, 5
• One study showed treatment failure was associated with male sex, urological abnormalities, and non-E. coli infections—all present in your scenario 5
• No guideline recommends fosfomycin for CA-UTI, and the IDSA CA-UTI guidelines do not mention it as a treatment option 1

Common Pitfalls to Avoid

• Do not treat asymptomatic bacteriuria in catheterized patients—this only promotes resistance without benefit 1, 2, 6
• Do not use empiric ciprofloxacin in urology patients or those with recent fluoroquinolone exposure 1
• Do not continue the old catheter during treatment if it has been in place ≥2 weeks 1, 2
• Do not use moxifloxacin for UTI due to uncertain urinary concentrations 1

Practical Treatment Algorithm

1. Confirm symptomatic UTI (fever, altered mental status, flank pain, costovertebral tenderness—not just positive culture) 1
2. Replace catheter if in place ≥2 weeks 1, 2
3. Obtain urine culture from new catheter before antibiotics 1, 2
4. Start empiric IV therapy with third-generation cephalosporin or aminoglycoside-containing combination 1
5. Tailor therapy based on culture results 1
6. Treat for 14 days in males (to cover possible prostatitis) 1
7. Remove catheter as soon as clinically appropriate 1, 2