What is the recommended antibiotic dosage for a male patient with a urinary tract infection (UTI) caused by methicillin-resistant Escherichia coli (E. coli) and Proteus?

Antibiotic Treatment for Male UTI with Methicillin-Resistant E. coli and Proteus

For male UTI with methicillin-resistant E. coli and Proteus, the recommended treatment is intravenous ceftazidime-avibactam 2.5g three times daily or meropenem-vaborbactam 2g three times daily for 14 days. 1

Understanding Male UTI as a Complicated Infection

• Male UTIs are classified as complicated infections according to European Urology guidelines, requiring longer treatment duration and broader antimicrobial coverage 2
• The presence of methicillin-resistant organisms further classifies this as a multidrug-resistant infection requiring specific antibiotic selection 1
• Common uropathogens in male UTIs include E. coli, Proteus species, Klebsiella species, Pseudomonas species, and Enterococcus species 2

First-Line Parenteral Treatment Options

• For methicillin-resistant E. coli and Proteus in male UTI, intravenous options include:

  • Ceftazidime-avibactam: 2.5g three times daily 1
  • Meropenem-vaborbactam: 2g three times daily 1
  • Cefiderocol: 2g three times daily 1
  • Piperacillin-tazobactam: 4.5g three times daily (for ESBL-E. coli only) 3

• Aminoglycosides may be considered as part of combination therapy:

  • Plazomicin: 15mg/kg once daily 1
  • Amikacin: 15mg/kg once daily 1

Oral Step-Down Options (After Clinical Improvement)

• After clinical improvement and based on susceptibility testing, consider:
  • Levofloxacin: 750mg once daily for 14 days (if susceptible) 1, 4
  • Ciprofloxacin: 500mg twice daily for 14 days (if susceptible) 1, 5
  • Trimethoprim-sulfamethoxazole: 160/800mg twice daily for 14 days (if susceptible) 2

Treatment Duration

• European Urology guidelines recommend 14 days of treatment for male UTIs when prostatitis cannot be excluded 1, 2
• A shorter duration (7 days) may be considered if the patient becomes afebrile within 48 hours and shows clear clinical improvement 1, 2

Important Clinical Considerations

• Obtain urine culture before initiating antibiotics to guide potential adjustments based on susceptibility results 2
• For methicillin-resistant organisms, traditional first-line agents like fluoroquinolones may have high resistance rates (up to 39.9% for E. coli) 6
• Consider local resistance patterns when selecting empiric therapy 3
• Evaluate for and address underlying urological abnormalities that may contribute to infection or recurrence 2

Common Pitfalls to Avoid

• Avoid fluoroquinolones as empiric therapy when resistance is suspected or when other effective options are available 2
• Inadequate treatment duration can lead to persistent or recurrent infection, particularly if prostate involvement is present 2
• Nitrofurantoin and fosfomycin have limited utility for complicated UTIs and should be reserved for lower UTIs only 7
• Failing to obtain urine culture before initiating antibiotics can complicate management if initial empiric therapy is ineffective 2

Alternative Options for Multidrug-Resistant Organisms

• For patients with allergies or contraindications to first-line agents:
  • Doxycycline may be effective if susceptibility is confirmed 8
  • Ceftolozane-tazobactam: 1.5g three times daily 1
  • Imipenem-cilastatin: 500mg three times daily 1