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

Treatment of Urinary Tract Infection

For uncomplicated cystitis in women, use first-line antibiotics—nitrofurantoin (100 mg twice daily for 5-7 days), trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3 days), or fosfomycin (3 g single dose)—based on local resistance patterns, with treatment duration no longer than 7 days. 1

Classification: Uncomplicated vs Complicated UTI

The treatment approach fundamentally depends on whether the UTI is uncomplicated or complicated:

Uncomplicated UTI occurs in nonpregnant, premenopausal women without structural/functional urinary tract abnormalities or relevant comorbidities. 1

Complicated UTI involves any of the following factors: 1

• Male sex
• Pregnancy
• Diabetes mellitus or immunosuppression
• Urinary tract obstruction or foreign body (catheter, stones)
• Structural abnormalities (cystocele, diverticula, fistulae)
• Recent instrumentation or surgery
• Incomplete voiding or vesicoureteral reflux
• Healthcare-associated infection
• Multidrug-resistant organisms

Treatment for Uncomplicated Cystitis in Women

First-Line Antibiotic Options

Choose based on local antibiogram and patient-specific factors: 1

• Fosfomycin trometamol: 3 g single dose (1 day) 1
• Nitrofurantoin: 50-100 mg four times daily OR 100 mg twice daily for 5 days 1
• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days (only if local E. coli resistance <20%) 1, 2
• Pivmecillinam: 400 mg three times daily for 3-5 days 1

Alternative Options

Use when first-line agents are contraindicated or based on resistance patterns: 1

• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days) if local E. coli resistance <20% 1
• Trimethoprim: 200 mg twice daily for 5 days (avoid in first trimester pregnancy) 1

Critical Caveat on Fluoroquinolones

Fluoroquinolones should NOT be used as first-line therapy for uncomplicated cystitis despite their efficacy, due to concerns about collateral damage (resistance development) and adverse effects. 1 Reserve ciprofloxacin only when: 1

• Local resistance rate is <10%
• Patient has anaphylaxis to β-lactams
• Entire treatment can be given orally without hospitalization

Treatment for Uncomplicated Cystitis in Men

Men require longer treatment duration: 1

• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 7 days 1
• Fluoroquinolones can be prescribed according to local susceptibility testing 1
• Consider 14-day course if prostatitis cannot be excluded 1

Treatment for Uncomplicated Pyelonephritis

For upper tract infection with fever (>38°C), flank pain, or systemic symptoms: 1

Oral therapy options (10-14 days): 1

• Ciprofloxacin: 500-750 mg twice daily for 7 days (if fluoroquinolone resistance <10%) 1
• Levofloxacin: 750 mg once daily for 5 days 1
• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 14 days 1
• Cefpodoxime: 200 mg twice daily for 10 days 1
• Ceftibuten: 400 mg once daily for 10 days 1

Important: If oral agents are used empirically, administer an initial intravenous dose of long-acting parenteral antibiotic (e.g., ceftriaxone). 1

Treatment for Complicated UTI

For patients with systemic symptoms requiring hospitalization, use combination intravenous therapy: 1

• Amoxicillin PLUS aminoglycoside, OR 1
• Second-generation cephalosporin PLUS aminoglycoside, OR 1
• Intravenous third-generation cephalosporin 1

Treatment duration: 7-14 days (14 days for men when prostatitis cannot be excluded). 1 When patient is hemodynamically stable and afebrile for ≥48 hours, consider shortening to 7 days. 1

Critical step: Obtain urine culture and susceptibility testing before initiating therapy, then tailor antibiotics to isolated uropathogen. 1 Address underlying urological abnormality—antimicrobial therapy alone is insufficient without correcting structural problems. 1

Diagnostic Approach

For Uncomplicated Cystitis

Obtain urine culture BEFORE treatment in patients with recurrent UTI (≥3 episodes/year or 2 episodes/6 months). 1 For first episodes in otherwise healthy women, urinalysis alone (including nitrite dipstick and leukocyte esterase) is sufficient—urine culture is unnecessary and adds cost. 3, 4

For All Pyelonephritis and Complicated UTI

Always obtain: 1

• Urinalysis with assessment of white/red blood cells and nitrite 1
• Urine culture and antimicrobial susceptibility testing 1
• Upper urinary tract ultrasound if history of urolithiasis, renal dysfunction, or high urine pH 1

Obtain CT scan or excretory urography if: 1

• Patient remains febrile after 72 hours of treatment
• Clinical deterioration occurs

Special Populations

Women with Diabetes

Treat similarly to women without diabetes for uncomplicated cystitis (no voiding abnormalities present). 5 However, diabetes is a risk factor for complicated UTI requiring longer treatment. 1

Postmenopausal Women

Use vaginal estrogen replacement to prevent recurrent UTI (strong recommendation). 1 This is distinct from systemic estrogen therapy, which does not reduce UTI risk. 1

Pregnant Women

• Avoid trimethoprim in first trimester 1
• Avoid trimethoprim-sulfamethoxazole in last trimester 1
• Use ultrasound or MRI (not CT) for imaging to avoid fetal radiation exposure 1

Management of Treatment Failure

If symptoms persist beyond 7 days after initiating therapy: 1

• Repeat urine culture to guide further management 1
• Obtain culture BEFORE starting second antibiotic 1
• Assume infecting organism is not susceptible to original agent 1
• Consider 7-day regimen with different antibiotic class 1

Asymptomatic Bacteriuria

Do NOT treat asymptomatic bacteriuria in non-pregnant women, even those with recurrent UTI history. 1 Do NOT perform surveillance urine cultures in asymptomatic patients. 1 Exceptions requiring treatment: pregnant women and patients scheduled for invasive urinary tract procedures. 1

Key Pitfalls to Avoid

• Do not use β-lactam agents (amoxicillin-clavulanate, cefpodoxime-proxetil) as empirical first-line therapy for uncomplicated cystitis—they are less effective. 1
• Do not use fluoroquinolones empirically in patients from urology departments or those who used fluoroquinolones in the last 6 months. 1
• Do not treat for longer than necessary—3-7 days is sufficient for uncomplicated cystitis; longer courses increase resistance without improving outcomes. 1
• Do not obtain routine post-treatment cultures in asymptomatic patients after successful treatment. 1