What are the recommended antibiotics for complex Urinary Tract Infections (UTIs)?

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Last updated: July 5, 2025View editorial policy

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From the Guidelines

For complex urinary tract infections (UTIs), the recommended antibiotics include a combination of amoxicillin plus an aminoglycoside, a second-generation cephalosporin plus an aminoglycoside, or an intravenous third-generation cephalosporin as empirical treatment, with treatment duration typically ranging from 7-14 days depending on severity, as stated in the 2024 European Association of Urology guidelines 1. The choice of antibiotic should be guided by culture and sensitivity testing, considering local resistance patterns, and empiric choices should be made with caution, avoiding the use of ciprofloxacin and other fluoroquinolones for empirical treatment of complicated UTI in patients from urology departments or when patients have used fluoroquinolones in the last 6 months 1. Some key points to consider when treating complex UTIs include:

  • Managing any urological abnormality and/or underlying complicating factors, as recommended by the European Association of Urology guidelines 1
  • Using a combination of antibiotics, such as amoxicillin plus an aminoglycoside, or a second-generation cephalosporin plus an aminoglycoside, as recommended by the guidelines 1
  • Avoiding the use of ciprofloxacin and other fluoroquinolones for empirical treatment of complicated UTI in certain patient populations, as recommended by the guidelines 1
  • Completing the full course of antibiotics even after symptoms resolve, maintaining adequate hydration, and following up to ensure infection clearance, as is standard practice in treating UTIs. Recent studies have shown that short-duration courses of antibiotics, such as 7-day treatment courses, can be effective for the management of complicated UTI and pyelonephritis, with appropriate diagnosis based on clinical response 1.

From the Research

Recommended Antibiotics for Complex UTIs

The following antibiotics are recommended for the treatment of complex Urinary Tract Infections (UTIs):

  • Nitrofurantoin
  • Fosfomycin tromethamine
  • Pivmecillinam
  • Fluoroquinolones
  • β-lactams, such as amoxicillin-clavulanate
  • Oral cephalosporins, such as cephalexin or cefixime
  • Carbapenems, such as meropenem/vaborbactam or imipenem/cilastatin-relebactam
  • Ceftazidime-avibactam
  • Ceftolozane-tazobactam
  • Aminoglycosides, including plazomicin
  • Cefiderocol
  • Colistin
  • Aztreonam 2

Treatment Options for Specific Types of Complex UTIs

UTIs due to ESBL-producing Enterobacteriales

  • Nitrofurantoin
  • Fosfomycin
  • Pivmecillinam
  • Amoxicillin-clavulanate
  • Finafloxacin
  • Sitafloxacin
  • Piperacillin-tazobactam (for ESBL-E coli only)
  • Carbapenems, including meropenem/vaborbactam or imipenem/cilastatin-relebactam
  • Ceftazidime-avibactam
  • Ceftolozane-tazobactam
  • Aminoglycosides, including plazomicin
  • Cefiderocol
  • Fosfomycin
  • Sitafloxacin
  • Finafloxacin 2

UTIs due to Carbapenem-resistant Enterobacteriales (CRE)

  • Ceftazidime-avibactam
  • Meropenem/vaborbactam
  • Imipenem/cilastatin-relebactam
  • Colistin
  • Fosfomycin
  • Aztreonam
  • Amoxicillin-clavulanate
  • Aminoglycosides, including plazomicin
  • Cefiderocol
  • Tigecycline 2

UTIs due to Multidrug-resistant (MDR)-Pseudomonas spp.

  • Fluoroquinolones
  • Ceftazidime
  • Cefepime
  • Piperacillin-tazobactam
  • Carbapenems, including imipenem/cilastatin/relebactam or meropenem
  • Fosfomycin
  • Ceftolozane-tazobactam
  • Ceftazidime-avibactam
  • Aminoglycosides, including plazomicin
  • Aztreonam
  • Cefiderocol
  • Colistin 2

Other Treatment Options

  • Ertapenem, a Group 1 carbapenem, has been shown to be effective in the treatment of complicated UTIs 3
  • Ceftriaxone, a broad-spectrum cephalosporin, has been used to treat complicated UTIs 4, 5
  • Ciprofloxacin, a fluoroquinolone, has been used to treat uncomplicated and complicated UTIs 4, 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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