What is the recommended treatment for a patient with a urinary tract infection (UTI)?

Treatment of Urinary Tract Infections

For uncomplicated UTIs in women, use nitrofurantoin 100 mg twice daily for 5 days, fosfomycin 3 g single dose, or trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days as first-line therapy, with the choice guided by local resistance patterns (TMP-SMX only if local resistance <20%). 1, 2

Uncomplicated Cystitis in Women

First-Line Treatment Options

• Nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days is preferred due to minimal resistance patterns and low collateral damage to normal vaginal and fecal flora 1, 2

• Fosfomycin trometamol 3 g as a single oral dose offers excellent compliance with convenient single-dose administration, though slightly lower efficacy than other first-line agents 1, 2

• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days should only be used if local resistance rates are documented to be <20% or if the infecting organism is known to be susceptible 1, 2, 3

When to Obtain Urine Culture

Urine culture is not routinely needed for typical uncomplicated cystitis presentations in women 1, 2. However, obtain culture before treatment when:

• Suspected acute pyelonephritis is present 1, 2
• Symptoms persist or recur within 4 weeks after treatment completion 1, 2
• Patient presents with atypical symptoms 2
• Patient is pregnant 1, 2
• Male patient (all UTIs in men are considered complicated) 1
• Recurrent infections (≥3 UTIs per year or ≥2 UTIs in 6 months) 1, 2

Critical Pitfall to Avoid

Do not use fluoroquinolones (ciprofloxacin, levofloxacin) as first-line therapy for uncomplicated cystitis. Reserve these agents for complicated infections or pyelonephritis to preserve efficacy and minimize resistance development 2. The guidelines consistently emphasize this restriction despite fluoroquinolone efficacy 1.

Acute Uncomplicated Pyelonephritis

Outpatient Oral Therapy (Mild-Moderate Cases)

For patients who can tolerate oral therapy and are hemodynamically stable:

• Ciprofloxacin 500-750 mg twice daily for 7 days (only if local fluoroquinolone resistance <10%) 1, 2
• Levofloxacin 750 mg once daily for 5 days (only if local fluoroquinolone resistance <10%) 1, 2
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 14 days (if organism susceptible) 1, 2
• Cefpodoxime 200 mg twice daily for 10 days or ceftibuten 400 mg once daily for 10 days (consider initial IV dose of ceftriaxone if using oral cephalosporin empirically) 1, 2

Inpatient Parenteral Therapy (Severe Cases)

For patients requiring hospitalization, initiate IV therapy:

• Ciprofloxacin 400 mg IV twice daily 1, 2
• Levofloxacin 750 mg IV once daily 1, 2
• Ceftriaxone 1-2 g IV once daily (higher 2 g dose recommended despite lower dose studied) 1, 2
• Cefotaxime 2 g IV three times daily 1
• Gentamicin 5 mg/kg IV once daily (with or without ampicillin) 1, 2
• Piperacillin/tazobactam 2.5-4.5 g IV three times daily 1

Once hemodynamically stable and afebrile for 24-48 hours, transition to oral step-down therapy to complete 7-14 days total treatment 1, 2.

Complicated UTIs

Defining Complicating Factors

A UTI is classified as complicated when any of these factors are present 1:

• Obstruction at any site in the urinary tract 1
• Foreign body (catheter, stent) 1
• Incomplete bladder voiding 1
• Vesicoureteral reflux 1
• Recent instrumentation 1
• Male gender (all UTIs in men are complicated) 1
• Pregnancy 1
• Diabetes mellitus 1
• Immunosuppression 1
• Healthcare-associated infection 1
• ESBL-producing or multidrug-resistant organisms 1

Management Principles

Always obtain urine culture and susceptibility testing before initiating antibiotics for complicated UTIs. 2 The microbial spectrum is broader than uncomplicated UTIs, including E. coli, Proteus spp., Klebsiella spp., Pseudomonas spp., Serratia spp., and Enterococcus spp., with higher antimicrobial resistance rates 1.

Initial empiric therapy should be based on:

• Severity of illness 2
• Risk factors for resistant organisms 2
• Local resistance patterns and antibiogram data 1, 2

Treat complicated UTIs for 7 days in women, but extend to 14 days in men when prostatitis cannot be excluded. 2

Empiric Therapy Options

For hemodynamically stable patients with complicated UTI:

• Fluoroquinolones (if local resistance <10%) 1, 2
• Extended-spectrum cephalosporins (ceftriaxone, cefotaxime, cefepime) 1, 2
• Extended-spectrum penicillins (piperacillin/tazobactam) 1, 2
• Aminoglycosides 1, 2

Reserve carbapenems and novel broad-spectrum agents (ceftolozane/tazobactam, ceftazidime/avibactam, cefiderocol, meropenem-vaborbactam) only for patients with early culture results indicating multidrug-resistant organisms. 1

Recurrent UTIs (rUTI)

Diagnostic Requirements

Document positive urine cultures associated with prior symptomatic episodes to diagnose rUTI (defined as ≥3 UTIs per year or ≥2 UTIs in 6 months). 1, 2

Obtain urine culture with each symptomatic acute cystitis episode prior to initiating treatment in rUTI patients. 1, 2 This provides baseline data for evaluating interventions and allows tailoring therapy based on bacterial sensitivities 1.

Treatment of Acute Episodes

• Treat acute cystitis episodes in rUTI patients for as short a duration as reasonable, generally no longer than 7 days. 1, 2
• Use first-line agents (nitrofurantoin, TMP-SMX, fosfomycin) dependent on local antibiogram 1
• Patient-initiated treatment (self-start) may be offered to select rUTI patients while awaiting culture results 1, 2

When Symptoms Persist After Treatment

If symptoms persist beyond 7 days after initiating therapy:

1. Obtain repeat urine culture before prescribing additional antibiotics 2
2. Switch to a different antimicrobial class based on culture and susceptibility results 2
3. Evaluate for underlying complicating factors (obstruction, incomplete emptying, stones, diabetes, immunosuppression) 1, 2

Critical pitfall: Do not treat asymptomatic bacteriuria if cultures show bacteria but symptoms have resolved, as this increases antimicrobial resistance and paradoxically increases recurrent UTI episodes. 2

Special Populations

Pregnancy

Asymptomatic bacteriuria must be screened for and treated in pregnant women (unlike non-pregnant women where it should not be treated). 2 Obtain urine culture before treatment 2.

Asymptomatic Bacteriuria (Non-Pregnant)

Do not screen for or treat asymptomatic bacteriuria except in:

• Pregnant women 1, 2
• Before invasive urologic procedures 1, 2

Treatment of asymptomatic bacteriuria in other populations increases antimicrobial resistance without clinical benefit 2.

Treatment Duration Principles

The evidence consistently supports shorter treatment courses:

• Uncomplicated cystitis: 3-5 days (nitrofurantoin 5 days, TMP-SMX 3 days, fosfomycin single dose) 1, 2
• Uncomplicated pyelonephritis: 5-7 days (fluoroquinolones 5-7 days, TMP-SMX 14 days, cephalosporins 10 days) 1, 2
• Complicated UTI: 7 days in women, 14 days in men 2
• Recurrent UTI acute episodes: ≤7 days 1, 2

Three-day regimens achieve symptomatic cure rates equivalent to 5-10 day courses, with significantly fewer adverse effects 2.