What is the recommended treatment for an uncomplicated urinary tract infection (UTI) in a non-pregnant, otherwise healthy adult woman?

Treatment of Uncomplicated UTI in Non-Pregnant Adult Women

Nitrofurantoin 100 mg twice daily for 5 days or fosfomycin 3g single dose are the recommended first-line treatments for uncomplicated UTI in non-pregnant, otherwise healthy adult women. 1, 2

First-Line Treatment Options

The European Association of Urology establishes three equally acceptable first-line agents that maintain high efficacy while minimizing collateral damage to normal flora 1, 2:

• Nitrofurantoin: 100 mg twice daily for 5 days (available as monohydrate, macrocrystals, or prolonged-release formulations) 2
• Fosfomycin trometamol: 3g single dose, taken with or without food, mixed with water before ingesting 2, 3
• Pivmecillinam: 400 mg three times daily for 3-5 days (where available) 2

Real-world evidence supports nitrofurantoin as the preferred first-line agent, showing lower treatment failure rates compared to trimethoprim-sulfamethoxazole, with only 0.3% risk of progression to pyelonephritis 4.

Second-Line Treatment Options

Use these agents only when first-line options are contraindicated or unavailable 2:

• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days—only if local E. coli resistance rates are below 20% 2, 5
• Trimethoprim alone: 200 mg twice daily for 5 days 2
• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days): only if local E. coli resistance is <20% 2

Diagnostic Approach

• Clinical diagnosis is sufficient in women presenting with acute-onset dysuria plus urgency/frequency, without vaginal discharge or irritation (>90% accuracy) 1
• Urine culture is NOT required for straightforward uncomplicated cystitis with typical symptoms 1, 2
• Obtain urine culture only in specific situations: suspected pyelonephritis, symptoms not resolving or recurring, atypical presentation, pregnancy, or recurrent UTIs 2

Critical Contraindications and Warnings

Nitrofurantoin should NOT be used for 2:

• Pyelonephritis (inadequate tissue penetration)
• Creatinine clearance <60 mL/min
• Infants under 4 months of age

Fosfomycin is NOT indicated for 3:

• Pyelonephritis or perinephric abscess
• If bacteriuria persists or reappears after treatment, select alternative agents

Avoid fluoroquinolones as first-line therapy due to FDA black box warnings for serious adverse effects, significant collateral damage promoting multi-drug resistant organisms, and the need to preserve effectiveness for complicated infections 1, 2, 6, 7

Common Pitfalls to Avoid

• Don't treat asymptomatic bacteriuria unless the patient is pregnant or undergoing urological procedures breaching the mucosa 1, 2
• Don't routinely obtain imaging or cystoscopy for uncomplicated recurrent UTIs in otherwise healthy women 1
• Don't use fluoroquinolones empirically given resistance concerns and safety warnings 1
• Don't use trimethoprim-sulfamethoxazole without knowing local resistance patterns—increasing resistance over time has led to higher treatment failure rates (1.6% higher prescription switch rate compared to nitrofurantoin) 4

Alternative Management Consideration

• For women with mild to moderate symptoms, symptomatic therapy with NSAIDs may be considered as an alternative to immediate antibiotic treatment 1
• However, NSAIDs probably result in less short-term symptom resolution (RR 0.67) and require more rescue antibiotic treatment by day 30 (RR 3.14) compared to primary antibiotic therapy 8
• This approach requires shared decision-making with patients who understand the trade-offs 1

Treatment Duration

• 5-7 days for nitrofurantoin 1
• 3-5 days maximum for most agents in uncomplicated cystitis 2
• Single dose for fosfomycin 2, 3