What is the drug of choice for a urinary tract infection (UTI) with a high white blood cell (WBC) count?

Drug of Choice for UTI with High WBC Count

Fluoroquinolones (specifically levofloxacin 750 mg daily for 5 days) are the recommended first-line treatment for urinary tract infections with elevated white blood cell counts, as they provide excellent coverage against common uropathogens and achieve high urinary concentrations. 1

Rationale for Treatment Selection

The presence of an elevated WBC count in a urinary tract infection suggests a more significant inflammatory response, potentially indicating pyelonephritis or a complicated UTI rather than simple cystitis. This distinction is crucial for treatment decisions:

• High WBC counts in urine correlate with higher likelihood of bacteriuria, with counts >25 cells/hpf associated with 53.8% rates of bacteriuria 2
• Elevated systemic inflammatory markers (including WBC) are significantly higher in patients with culture-positive UTIs 3

Treatment Algorithm

First-line Options:

1. Oral therapy (for stable patients without severe symptoms):

   • Levofloxacin 750 mg once daily for 5 days 1, 4
   • Ciprofloxacin 500-750 mg twice daily for 7 days 1

2. Parenteral therapy (for severe symptoms, signs of sepsis, or inability to tolerate oral medications):

   • Ciprofloxacin 400 mg IV twice daily 1
   • Levofloxacin 750 mg IV once daily 1
   • Ceftriaxone 1-2 g IV once daily 1

Alternative Options (if fluoroquinolone resistance >10% or contraindicated):

• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 14 days 1
• Cephalosporins (oral cefpodoxime 200 mg twice daily or ceftibuten 400 mg daily for 10 days) 1

Special Considerations

Complicated vs. Uncomplicated UTI

• The presence of high WBC counts may indicate pyelonephritis or a complicated UTI
• Prompt differentiation between uncomplicated and potentially obstructive pyelonephritis is crucial, as the latter can rapidly progress to urosepsis 1

Diagnostic Approach

• Urinalysis with assessment of WBC and nitrite is recommended for routine diagnosis 1
• Urine culture and antimicrobial susceptibility testing should be performed in all cases of suspected pyelonephritis or complicated UTI 1
• WBC >25 cells/hpf represents the optimal cutoff for predicting bacteriuria (sensitivity 57.4%, specificity 81.1%) 2, 5

Treatment Duration

• 5 days for uncomplicated UTI with fluoroquinolones
• 7-14 days for complicated UTI or pyelonephritis 1

Monitoring and Follow-up

• Clinical improvement should be expected within 48-72 hours of initiating appropriate therapy
• If fever persists after 72 hours of treatment, or if there is clinical deterioration, additional imaging (contrast-enhanced CT) should be considered to rule out complications 1

Important Caveats

1. Local resistance patterns should be considered when selecting empiric therapy. Fluoroquinolones should only be used as first-line when local resistance is <10% 1

2. Avoid nitrofurantoin, oral fosfomycin, and pivmecillinam for UTIs with high WBC counts as there are insufficient data regarding their efficacy in upper UTIs 1

3. Reserve carbapenems and novel broad-spectrum antimicrobials for patients with early culture results indicating multidrug-resistant organisms 1

4. Adjust therapy based on culture and susceptibility results when available to ensure targeted treatment and reduce unnecessary broad-spectrum antibiotic use