What is the recommended treatment for an uncomplicated urinary tract infection (UTI)?

Treatment of Uncomplicated Urinary Tract Infection

For uncomplicated UTI in women, use nitrofurantoin 100 mg twice daily for 5 days, fosfomycin 3 grams as a single dose, or trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days as first-line therapy, with selection based on local resistance patterns. 1, 2

First-Line Antibiotic Options

The choice among first-line agents should be guided by your local antibiogram, with the following hierarchy:

• Nitrofurantoin: 50-100 mg four times daily OR 100 mg twice daily for 5 days 1, 2, 3

  • Preferred due to minimal collateral damage to normal flora and low resistance rates 2
  • Effective for bladder infections with minimal resistance development 3

• Fosfomycin trometamol: 3 grams as a single oral dose 1, 2, 3

  • FDA-approved specifically for uncomplicated cystitis in women 4
  • Offers convenience of one-time dosing 3
  • Should be mixed with water before ingestion, never taken in dry form 4

• Trimethoprim-sulfamethoxazole (TMP-SMX): 160/800 mg twice daily for 3 days 1, 2, 5

  • Only use if local E. coli resistance is <20% 1, 3
  • Avoid in first trimester of pregnancy (trimethoprim) and last trimester (TMP-SMX) 1, 3

Treatment Duration

Treat for as short a duration as reasonable, generally no longer than 7 days. 1, 2

• For uncomplicated cystitis: 3-5 days depending on agent selected 1
• Single-dose antibiotics (except fosfomycin) show higher bacteriological persistence rates (RR 2.01 for short-course, RR 1.93 for long-course) and should be avoided 1, 2
• Three-day therapy achieves similar symptomatic cure as 5-10 day therapy but with fewer adverse effects (RR 0.83) 6

Alternative Agents (Second-Line)

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

• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days): Only if local E. coli resistance <20% 1
• Pivmecillinam: 400 mg three times daily for 3-5 days 1
• Trimethoprim alone: 200 mg twice daily for 5 days (not in first trimester of pregnancy) 1

Agents to AVOID as First-Line

Do not use fluoroquinolones (ciprofloxacin, levofloxacin) as first-line therapy. 2

• Unfavorable risk-benefit ratio for uncomplicated UTI 2
• Significant collateral damage to normal flora 1, 2
• Increasing resistance rates 2
• Reserve for complicated infections or pyelonephritis 1

Treatment in Men

Men with uncomplicated UTI require longer treatment duration:

• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 7 days 1
• Nitrofurantoin or trimethoprim: 7-day course 7
• Always obtain urine culture before treatment to guide antibiotic selection 7
• Consider prostatitis as alternative diagnosis, which requires 14 days of treatment 1

When to Obtain Urine Culture

Obtain urine culture and susceptibility testing in these situations: 1, 2

• Suspected acute pyelonephritis (fever, flank pain, systemic symptoms) 1, 3
• Symptoms not resolving or recurring within 4 weeks after treatment completion 1, 2
• Atypical symptoms or unclear diagnosis 1
• Pregnant women 1, 3
• Men with UTI symptoms 7
• History of resistant organisms 7
• Recurrent UTIs (≥3 per year or ≥2 in 6 months) 2

Treatment Failure Management

If symptoms persist after completing treatment:

• Obtain urine culture with susceptibility testing 1, 2, 3
• Assume resistance to initial antibiotic 1, 3
• Retreat with a different antibiotic class for 7 days 1, 3
• Consider alternative diagnoses if symptoms recur within 2 weeks 1

Asymptomatic Bacteriuria

Do not treat asymptomatic bacteriuria in non-pregnant patients. 1, 2

• Do not perform surveillance urine testing in asymptomatic patients with history of recurrent UTIs 1, 2
• Exceptions requiring treatment: pregnancy and patients scheduled for invasive urinary procedures 1, 2
• Treatment increases risk of symptomatic infection, bacterial resistance, and healthcare costs 2

Critical Warning Signs Requiring Different Management

Refer or escalate care if patient has: 3

• Fever, chills, or rigors (suggests pyelonephritis) 3
• Flank pain or back pain (suggests upper tract involvement) 3
• Nausea or vomiting (suggests systemic infection) 3
• Vaginal discharge (suggests alternative diagnosis) 3
• Pregnancy 1, 3

Common Pitfalls to Avoid

• Do not treat based on symptoms alone in recurrent UTI patients - obtain culture first to avoid inappropriate antibiotic selection 2
• Do not use single-dose regimens (except fosfomycin) - associated with higher treatment failure rates 1, 2
• Do not prescribe fluoroquinolones as first-line - reserve for complicated infections 2
• Do not treat asymptomatic bacteriuria - increases resistance and costs without benefit 1, 2
• Do not use TMP-SMX if local resistance >20% - check your local antibiogram 1