What are the current guidelines for managing uncomplicated and complicated urinary tract infections (UTIs)?

Current Guidelines for Managing Urinary Tract Infections (UTIs)

First-line antibiotics for uncomplicated UTIs should include nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin, with treatment duration generally no longer than seven days. 1

Uncomplicated UTIs

Diagnosis

• Obtain urine culture before starting antibiotics to guide targeted therapy if empiric treatment fails 2
• Avoid surveillance urine testing in asymptomatic patients with recurrent UTIs 1
• Asymptomatic bacteriuria should not be treated except in specific populations (pregnant women or prior to urinary tract procedures) 1

Treatment Recommendations

• First-line therapy options:

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

• Treatment duration: As short as reasonable, generally no longer than 7 days 1

• Avoid fluoroquinolones for uncomplicated UTIs due to "collateral damage" (selection of multi-resistant pathogens) 1, 4

Complicated UTIs

Definition and Risk Factors

• Complicated UTIs occur when host-related factors or anatomic/functional abnormalities make infection more challenging to eradicate 1
• Common factors include:
  • Obstruction at any site in the urinary tract
  • Foreign body presence
  • Incomplete voiding
  • Vesicoureteral reflux
  • Recent instrumentation
  • Male gender
  • Pregnancy
  • Diabetes mellitus
  • Immunosuppression
  • Healthcare-associated infections
  • ESBL-producing or multidrug-resistant organisms 1

Microbiology

• More diverse microbial spectrum than uncomplicated UTIs 1
• Common pathogens include E. coli, Proteus spp., Klebsiella spp., Pseudomonas spp., Serratia spp., and Enterococcus spp. 1
• Higher likelihood of antimicrobial resistance 1

Treatment Recommendations

• Obtain urine culture and susceptibility testing before starting antibiotics 1
• Treatment duration: 7-14 days (14 days for men when prostatitis cannot be excluded) 1
• Consider shorter treatment (7 days) when patient is hemodynamically stable and afebrile for at least 48 hours 1
• Empiric therapy options:
  • Ciprofloxacin 500-750mg twice daily for 7 days (if local fluoroquinolone resistance <10%) 2
  • Levofloxacin 750mg once daily for 5 days 2
  • Cefuroxime 500mg twice daily for 10-14 days 5
  • For parenteral therapy: ceftriaxone, cefepime, piperacillin-tazobactam, or aminoglycosides 1, 6

Pyelonephritis

Diagnosis

• Prompt differentiation between uncomplicated and potentially obstructive pyelonephritis is crucial 1
• Consider imaging (contrast-enhanced CT or excretory urography) if patient remains febrile after 72 hours of treatment 1
• For pregnant women, use ultrasound or MRI to avoid radiation risk 1

Treatment Recommendations

• Oral therapy options:

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

• Parenteral therapy options:

  • Ciprofloxacin 400mg twice daily 1
  • Levofloxacin 750mg once daily 1
  • Ceftriaxone 1-2g once daily 1
  • Cefepime 1-2g twice daily 1, 6
  • Piperacillin-tazobactam 2.5-4.5g three times daily 1
  • Aminoglycosides (gentamicin 5mg/kg once daily or amikacin 15mg/kg once daily) 1

• For fluoroquinolones, local resistance should be <10% 1

• If using oral agents empirically, consider an initial intravenous dose of a long-acting parenteral antimicrobial (e.g., ceftriaxone) 1

Catheter-Associated UTIs

• Refers to UTI occurring in patients currently catheterized or catheterized within the past 48 hours 1
• Leading cause of secondary healthcare-associated bacteremia with approximately 10% mortality 1
• Incidence of bacteriuria with indwelling catheterization is 3-8% per day 1
• Catheterization duration is the most important risk factor 1

Antibiotic Resistance Considerations

• E. coli resistance rates to TMP-SMX are increasing; not recommended as first-line if local resistance exceeds 20% 1, 7
• Fluoroquinolone resistance rates in uncomplicated UTIs are still below 10% in some regions but increasing significantly 1, 7
• For recurrent UTIs, resistance rates are generally higher, particularly for trimethoprim (21.4%) and cotrimoxazole (19.3%) 7
• Consider local antibiograms when selecting empiric therapy 4

Special Considerations

• For patients with diabetes mellitus and chronic kidney disease (complicated UTI), fluoroquinolones may be appropriate when local resistance is low 2
• For severe or complicated UTIs, consider initial IV therapy before transitioning to oral antibiotics 5
• Follow-up urine culture after completion of therapy may be considered for complicated UTIs to ensure resolution 5