What is the treatment for urinary tract infections (UTIs)?

Treatment for Urinary Tract Infections

First-Line Antibiotic Selection

For uncomplicated cystitis in women, nitrofurantoin for 5 days is the preferred first-line agent, followed by trimethoprim-sulfamethoxazole (TMP-SMX) for 3 days or fosfomycin as a single dose, with selection dependent on local resistance patterns. 1

Uncomplicated Cystitis Treatment Options:

• Nitrofurantoin: 5-day course is recommended as the drug of choice due to robust efficacy evidence and minimal collateral damage to gut flora 1

• TMP-SMX: 3-day course is appropriate only when local resistance rates are <20% 1, 2

• Fosfomycin: Single 3-gram dose provides convenient alternative therapy 1

• Fluoroquinolones: 3-day course (ciprofloxacin or levofloxacin) should be reserved for second-line use due to resistance concerns and collateral damage 1

• Pivmecillinam: 3-day course where available 1

Duration Principles:

Treat acute cystitis episodes with the shortest reasonable duration, generally no longer than 7 days. 1

Pyelonephritis Management

For uncomplicated pyelonephritis, oral fluoroquinolones (ciprofloxacin 500-750mg twice daily for 7 days or levofloxacin 750mg daily for 5 days) are recommended when local resistance is <10%. 3

Pyelonephritis Treatment Algorithm:

• Low resistance areas (<10%): Oral fluoroquinolones for 5-7 days 3, 4

• High resistance areas: Initial parenteral ceftriaxone (third-generation cephalosporin) followed by oral step-down therapy 1, 3

• First-generation cephalosporins or TMP-SMX: Reasonable alternatives based on local susceptibility patterns 1

• Total duration: Typically 7-14 days depending on clinical response 1

Complicated UTI Treatment

Complicated UTIs require 7-14 days of treatment (14 days for men when prostatitis cannot be excluded), with empiric therapy guided by severity and local resistance patterns. 1, 3

Empiric Therapy for Complicated UTIs:

• Combination therapy is recommended initially 1:

  • Amoxicillin plus aminoglycoside, OR
  • Second-generation cephalosporin plus aminoglycoside, OR
  • Intravenous third-generation cephalosporin

• Broader microbial spectrum: E. coli, Proteus, Klebsiella, Pseudomonas, Serratia, and Enterococcus species are common 1

• Mandatory: Address underlying urological abnormality or complicating factor 1

• Culture-directed therapy: Obtain urine culture before treatment and tailor antibiotics based on susceptibilities 1

Complicated UTI Risk Factors to Identify:

• Urinary tract obstruction, foreign bodies, incomplete voiding, vesicoureteral reflux 1
• Male sex, pregnancy, diabetes mellitus, immunosuppression 1
• Recent instrumentation, healthcare-associated infections 1
• ESBL-producing or multidrug-resistant organisms 1

Catheter-Associated UTI (CAUTI)

For symptomatic CAUTI, remove or replace the catheter when possible and treat for 7-14 days based on clinical severity. 1

• Key symptoms: New fever, rigors, altered mental status, flank pain, costovertebral tenderness, acute hematuria, pelvic discomfort 1

• Catheter duration is the most important risk factor for CAUTI development 1

• Mortality risk: Approximately 10% for hospital-acquired bacteremia from urinary source 1

Pediatric UTI Treatment

For febrile infants and children 2-24 months with UTI, treat with oral or parenteral antimicrobials effective against common uropathogens for 7-14 days. 1

• Obtain urine culture by catheterization or suprapubic aspiration before starting antibiotics 1

• Adjust therapy based on antimicrobial sensitivities once available 1

• Follow-up within 1-2 days to ensure clinical improvement 1

• Imaging: Obtain renal and bladder ultrasound after confirmed UTI 1

Asymptomatic Bacteriuria (ASB)

Do not treat asymptomatic bacteriuria except in pregnant patients and those undergoing invasive urologic procedures with expected mucosal bleeding. 1

• Pregnant patients: Treat for 3-5 days depending on antimicrobial used 1, 3

• Urologic procedures: Single preoperative prophylactic dose is often sufficient 1

• Do not perform surveillance urine testing in asymptomatic patients 1

• Harm from treatment: Unnecessary antibiotics cause side effects, promote resistance, and provide no benefit 1

Multidrug-Resistant Organisms

For UTIs caused by multidrug-resistant organisms, treatment duration should match the anatomical location (cystitis vs pyelonephritis) and does not need to be extended solely due to resistance. 1

Treatment Options by Resistance Pattern:

• ESBL-producing organisms: Nitrofurantoin, fosfomycin, pivmecillinam for cystitis; carbapenems, ceftazidime-avibactam, or piperacillin-tazobactam for pyelonephritis 5, 6

• Carbapenem-resistant Enterobacteriaceae: Ceftazidime-avibactam, meropenem-vaborbactam, imipenem-cilastatin-relebactam, cefiderocol, or colistin 5, 6

• MDR Pseudomonas: Ceftolozane-tazobactam, ceftazidime-avibactam, or cefiderocol 5, 6

Antimicrobial Stewardship Principles

Deescalate antibiotics based on culture results and transition to oral therapy when clinically appropriate to reduce hospital length of stay and adverse events. 1, 3

• Oral regimens show comparable outcomes to intravenous-only treatment for most UTIs 1, 3

• Avoid fluoroquinolones for empiric therapy when alternatives exist due to resistance and collateral damage concerns 1, 6

• Patient-initiated treatment: Consider self-start therapy in select patients with recurrent UTIs while awaiting culture results 1

Critical Diagnostic Considerations

Always obtain urine culture and sensitivity before initiating treatment in patients with recurrent UTIs, complicated UTIs, or treatment failures. 1

• Urinalysis limitations: Positive UA in catheterized patients has very low specificity but excellent negative predictive value 1

• Culture interpretation: Lack of correlation between microbiological data and symptoms should prompt consideration of alternative diagnoses 1

• Avoid treating positive cultures without corresponding symptoms 1