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

Treatment of Uncomplicated UTI in Adult Females

For an adult, non-pregnant female with acute uncomplicated cystitis, use nitrofurantoin 100 mg twice daily for 5 days as first-line therapy, with fosfomycin 3 g single dose or trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days as alternatives based on local resistance patterns. 1

First-Line Antibiotic Selection

The choice among first-line agents depends critically on your local antibiogram and specific patient factors 2:

Preferred First-Line Options

• Nitrofurantoin monohydrate/macrocrystals: 100 mg twice daily for 5 days 2, 1, 3

  • Maintains excellent activity against E. coli despite 60+ years of use 4
  • Minimal collateral damage to normal flora 5
  • Contraindicated in renal impairment and last trimester of pregnancy 4

• Fosfomycin trometamol: 3 g single oral dose 1, 5, 3

  • Equally effective alternative with convenience of single-dose therapy 1
  • Particularly useful for patient adherence concerns 5

• Trimethoprim-sulfamethoxazole (TMP-SMX): 160/800 mg (1 DS tablet) twice daily for 3 days 2, 6, 3

  • Only use if local E. coli resistance is documented <20% 1
  • Rising resistance rates globally have demoted this from universal first-line status 2
  • FDA-approved dosing for UTI is 10-14 days, but guideline-recommended duration is 3 days for uncomplicated cystitis 6, 2

• Pivmecillinam: 400 mg three times daily for 3-5 days (where available) 1

  • Limited collateral damage profile 1
  • Not widely available in the United States 5

Second-Line Alternatives

Use these only when first-line agents cannot be used due to resistance, allergy, or contraindications 2:

• Fluoroquinolones (ciprofloxacin, levofloxacin): 3-day regimens are highly efficacious 2

  • Should be reserved for serious infections, not simple cystitis 2, 1
  • Propensity for collateral damage and promotion of resistance 2

• β-lactams (amoxicillin-clavulanate, cefdinir, cefpodoxime-proxetil): 3-7 day regimens 2

  • Generally inferior efficacy and more adverse effects compared to first-line agents 2
  • Cephalexin less well-studied but may be appropriate in certain settings 2
  • Never use amoxicillin or ampicillin alone due to very high resistance rates worldwide 2

Treatment Duration

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

• Nitrofurantoin: 5 days 1, 3
• Fosfomycin: Single dose 1, 3
• TMP-SMX: 3 days 2, 3
• Trimethoprim alone: 3 days 3
• For men with uncomplicated UTI: 7 days minimum 3

Diagnostic Approach

When Culture is NOT Required

• Self-diagnosis with classic symptoms (frequency, urgency, dysuria, nocturia, suprapubic pain) without vaginal discharge is >90% accurate 1, 3
• Empiric treatment without culture is appropriate for typical uncomplicated cystitis 1

When Culture IS Required Before Treatment

Obtain urine culture and sensitivity in these specific scenarios 2, 1:

• Suspected pyelonephritis 1
• Symptoms persisting >4 weeks after treatment 1
• Pregnant women 1
• Previous resistant isolates 1, 3
• Recurrent UTIs (obtain with each symptomatic episode) 2
• Treatment failure 3
• Atypical presentation 3
• Men with UTI symptoms (always) 3
• Adults ≥65 years old 3

Critical Pitfalls to Avoid

Do NOT Do These Things

• Do not treat asymptomatic bacteriuria unless pregnant or undergoing urologic procedures 2, 1
• Do not obtain surveillance urine testing in asymptomatic patients with history of recurrent UTI 2
• Do not routinely perform cystoscopy or upper tract imaging for uncomplicated recurrent UTI 2, 1
• Do not use fluoroquinolones empirically for simple cystitis given their importance for serious infections 1
• Do not use amoxicillin/ampicillin alone due to very high global resistance 2

Resistance Considerations

• Check your local antibiogram before selecting empiric therapy - resistance patterns vary significantly by region 2, 1
• TMP-SMX resistance among community E. coli has risen dramatically worldwide, necessitating revision of older recommendations 2, 7
• In vitro resistance correlates with clinical failure 2

Special Populations

• Men with lower UTI symptoms: Always treat with antibiotics and obtain culture; consider urethritis and prostatitis in differential 3
• Pregnant women: Require culture before treatment; nitrofurantoin contraindicated in last trimester 1, 4
• Renal impairment: Nitrofurantoin contraindicated at any degree of renal dysfunction 4

Patient-Initiated Treatment

For select patients with recurrent UTI, you may offer self-start treatment while awaiting culture results 2:

• Appropriate for reliable patients with well-documented recurrent UTI pattern 2
• Culture should still be obtained before initiating antibiotics 2