What is the treatment for acute complicated urinary tract infections (UTIs) versus uncomplicated UTIs?

Treatment for Acute Complicated UTIs vs Uncomplicated UTIs

Complicated UTIs require broader-spectrum antibiotics and longer treatment duration than uncomplicated UTIs, with therapy tailored to the underlying complicating factors and local resistance patterns. 1

Definition of Complicated UTI

A complicated UTI (cUTI) occurs when a patient has host-related factors or specific anatomic/functional abnormalities in the urinary tract that make the infection more challenging to eradicate compared to an uncomplicated infection. 1

Common factors associated with complicated UTIs:

• Obstruction at any site in the urinary tract 1
• Foreign body (including indwelling catheters) 1
• Incomplete voiding 1
• Vesicoureteral reflux 1
• Recent history of instrumentation 1
• ESBL-producing organisms 1
• UTI in males 1
• Pregnancy 1
• Diabetes mellitus 1
• Immunosuppression 1
• Healthcare-associated infections 1
• Multidrug-resistant organisms 1

Microbial Spectrum Differences

• Uncomplicated UTIs: Predominantly caused by E. coli 1
• Complicated UTIs: Broader spectrum including E. coli, Proteus spp., Klebsiella spp., Pseudomonas spp., Serratia spp., and Enterococcus spp., with higher likelihood of antimicrobial resistance 1

Treatment Algorithm

1. Uncomplicated UTIs (Cystitis)

First-line oral therapy options:

• Nitrofurantoin 100 mg twice daily for 5 days 1
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (if local resistance <20%) 1
• Fosfomycin trometamol 3 g single dose 1

Second-line options:

• Fluoroquinolones (only when other options cannot be used due to collateral damage concerns) 1
• β-lactams (e.g., amoxicillin-clavulanate, cefdinir) for 3-7 days 1

2. Uncomplicated Pyelonephritis

Outpatient oral therapy:

• Ciprofloxacin 500-750 mg twice daily for 7 days 1
• Levofloxacin 750 mg once daily for 5 days 1
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 14 days 1
• Cefpodoxime 200 mg twice daily for 10 days 1
• Ceftibuten 400 mg once daily for 10 days 1

For hospitalized patients (initial IV therapy):

• Ciprofloxacin 400 mg twice daily 1
• Levofloxacin 750 mg once daily 1
• Ceftriaxone 1-2 g once daily 1
• Cefepime 1-2 g twice daily 1
• Piperacillin/tazobactam 2.5-4.5 g three times daily 1
• Aminoglycosides (with or without ampicillin) 1

3. Complicated UTIs

Key principles:

• Obtain urine culture and susceptibility testing before starting therapy 1
• Address underlying urological abnormality or complicating factor 1
• Consider broader spectrum antibiotics initially 1

Treatment duration:

• 7-14 days generally recommended 1
• 14 days for men when prostatitis cannot be excluded 1
• May consider shorter duration (7 days) when patient is hemodynamically stable and afebrile for at least 48 hours 1

Antibiotic options:

• Similar to those for pyelonephritis but with consideration for broader spectrum coverage 1
• Carbapenems and novel broad-spectrum agents should be reserved for patients with multidrug-resistant organisms 1

4. Catheter-Associated UTIs

• 7-14 day regimen recommended for most patients with CA-UTI 1
• 5-day regimen with levofloxacin may be sufficient for mild CA-UTI 1
• 3-day regimen may be considered for women aged ≤65 years with mild CA-UTI after catheter removal 1
• Always discontinue catheter as soon as appropriate 1

Important Considerations

1. Local resistance patterns: Treatment should be guided by local antimicrobial resistance data 1

2. Fluoroquinolone use: Should be limited due to collateral damage concerns and reserved for situations where other options cannot be used 1, 2

   • For empiric therapy, fluoroquinolone resistance should be <10% 1

3. Duration of therapy: Shorter durations are preferred when appropriate to limit development of resistance 1

4. Tailoring therapy: Adjust regimen based on culture results and clinical response 1

5. Multidrug-resistant organisms: For ESBL-producing or carbapenem-resistant organisms, consult infectious disease specialists and consider newer agents like ceftazidime-avibactam, meropenem-vaborbactam, or cefiderocol 2

Pitfalls to Avoid

• Treating asymptomatic bacteriuria (except in pregnancy or before urologic procedures) 1
• Using fluoroquinolones as first-line for uncomplicated UTIs 1
• Using amoxicillin or ampicillin for empiric therapy due to high resistance rates 1
• Failing to adjust therapy based on culture results 1
• Not addressing underlying anatomical or functional abnormalities in complicated UTIs 1
• Using unnecessarily prolonged antibiotic courses 1