What is the recommended management for resistant urinary tract infections (UTIs)?

Management of Resistant Urinary Tract Infections

For resistant urinary tract infections (UTIs), the recommended management includes using ceftriaxone as first-line intravenous therapy, with alternative options including nitrofurantoin, fosfomycin, or pivmecillinam based on susceptibility testing, while avoiding fluoroquinolones due to increasing resistance rates. 1

Initial Assessment and Diagnosis

• Obtain urine culture and susceptibility testing before initiating therapy for resistant UTIs
• Consider risk factors for multidrug-resistant organisms:
  • Recent antibiotic exposure (especially fluoroquinolones)
  • Healthcare-associated infections
  • Recent hospitalization
  • Recurrent UTIs
  • Structural or functional urinary tract abnormalities

Empiric Treatment Options

For Patients Requiring Oral Therapy:

1. First-line options (based on local resistance patterns):

   • Nitrofurantoin 100 mg twice daily for 5 days (for lower UTIs only) 1
   • Fosfomycin trometamol 3 g single dose (for uncomplicated lower UTIs) 1
   • Pivmecillinam 400 mg twice daily for 3 days 1

2. Second-line options (when first-line agents cannot be used):

   • β-lactams for 7-day course 1
   • Levofloxacin 750 mg once daily for 5 days (only if local resistance <10%) 1, 2

For Patients Requiring Intravenous Therapy:

• Ceftriaxone is recommended as first-line for patients requiring IV therapy 1
• For suspected multidrug-resistant pathogens, consider:
  • Piperacillin-tazobactam (for ESBL-E. coli) 3
  • Carbapenems (for ESBL-producing Enterobacteriales) 3
  • Ceftazidime-avibactam or ceftolozane-tazobactam (for resistant Pseudomonas) 3

Treatment Duration

• Uncomplicated cystitis: 3-5 days 1
• Complicated UTIs: 7-14 days 1
• Pyelonephritis: 7-14 days 1
• Gram-negative bacteremia from urinary source: 7 days 1

Special Considerations

Dosing Adjustments for Renal Impairment

For fluoroquinolones (when necessary):

• CrCl >50 mL/min: Standard dose
• CrCl 30-50 mL/min: 250-500 mg every 12 hours
• CrCl 5-29 mL/min: 250-500 mg every 18 hours 1

For levofloxacin specifically:

• CrCl ≥50 mL/min: Standard dosing
• CrCl 26-49 mL/min: 500 mg once daily
• CrCl 10-25 mL/min: 250 mg once daily 1

High-Risk Populations

• Pregnant women: Avoid trimethoprim-sulfamethoxazole in first trimester and near term 1
• Elderly patients: Use nitrofurantoin with caution due to risk of adverse effects 1
• Patients with renal insufficiency: Adjust doses or avoid certain antibiotics based on renal function 1

Management of Specific Resistant Pathogens

ESBL-Producing Organisms

• Oral options: nitrofurantoin, fosfomycin, pivmecillinam (for E. coli) 3
• IV options: carbapenems, ceftazidime-avibactam 3

Carbapenem-Resistant Enterobacteriales (CRE)

• Limited options include ceftazidime-avibactam, colistin, fosfomycin 3

Multidrug-Resistant Pseudomonas

• Options include ceftolozane-tazobactam, ceftazidime-avibactam, cefiderocol 3

Prevention of Recurrent UTIs

• Increase fluid intake (goal of at least 2L of urine output daily) 1
• Vaginal estrogen for postmenopausal women 1
• Consider prophylactic antibiotics for 6-12 months in elderly women with recurrent UTIs 1
• Post-coital antibiotic prophylaxis for UTIs related to sexual activity 1

Common Pitfalls to Avoid

• Avoid treating asymptomatic bacteriuria except in pregnant women or before urological procedures 1
• Avoid fluoroquinolones as empiric therapy due to high resistance rates and risk of adverse effects 1, 4
• Avoid subtherapeutic doses which favor selection of resistant strains 1
• Avoid prolonged use of fluoroquinolones (>6 months) without rotation as this is associated with resistance development 1
• Avoid not adjusting antibiotic dosing based on renal function 1

Follow-up

• Clinical improvement should be expected within 48-72 hours 1
• Control cultures are not required if symptoms resolve 1
• Consider urological evaluation for recurrent or complicated UTIs 1
• Consider cystoscopy if hematuria is present or if symptoms persist despite treatment 1

By following these evidence-based recommendations and considering local resistance patterns, clinicians can effectively manage resistant UTIs while minimizing the development of further antimicrobial resistance.