What is the treatment for an uncomplicated urinary tract infection (UTI) in a healthy adult?

Treatment of Uncomplicated Urinary Tract Infections in Healthy Adults

For uncomplicated UTIs in healthy adult women, first-line treatment consists of nitrofurantoin 100 mg twice daily for 5 days, fosfomycin 3 g single dose, or trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (only if local resistance is <20%). 1, 2, 3

First-Line Antibiotic Options

Nitrofurantoin (Preferred)

• Dose: 100 mg twice daily for 5 days 1, 2, 3
• Minimal resistance rates and low propensity for collateral damage (selection of multidrug-resistant organisms) 2, 4
• Highly effective with excellent urinary concentrations 5

Fosfomycin Trometamol

• Dose: 3 g single dose 1, 2, 3
• Convenient single-dose regimen, though slightly lower efficacy than nitrofurantoin 2
• Minimal collateral damage to normal flora 6
• Recommended specifically for women with uncomplicated cystitis 1

Trimethoprim-Sulfamethoxazole

• Dose: 160/800 mg (1 double-strength tablet) twice daily for 3 days 2, 7, 3
• Critical caveat: Only use if local E. coli resistance rates are <20% or if the organism is known to be susceptible 1, 2, 6
• Increasing resistance rates have demoted this from universal first-line status 6
• Avoid if patient received this antibiotic recently, as prior exposure increases resistance risk 1, 6

When to Obtain Urine Culture

Do NOT routinely obtain urine culture for typical uncomplicated cystitis in women. 1, 3

Obtain urine culture in these situations:

• Suspected acute pyelonephritis 1
• Symptoms that do not resolve or recur within 4 weeks after treatment 1
• Atypical symptoms 1
• Pregnant women 1
• Men with UTI symptoms 3
• Recurrent UTIs (≥3 UTIs/year or ≥2 UTIs in 6 months) - obtain culture with each symptomatic episode before treatment 1, 2
• Older adults ≥65 years 2, 3
• History of resistant organisms 3

Diagnosis Without Laboratory Testing

In women with typical acute-onset dysuria plus urgency/frequency, without vaginal discharge or irritation, you can diagnose and treat uncomplicated cystitis based on symptoms alone. 1, 3

• Dysuria has >90% accuracy for UTI in young women when vaginal symptoms are absent 1
• Dipstick testing adds minimal diagnostic value when symptoms are typical 1

Second-Line Options

Use when first-line agents are contraindicated or unavailable:

• Fluoroquinolones (ciprofloxacin, levofloxacin): Reserve due to increasing resistance rates and significant collateral damage 1, 6, 8
• Oral cephalosporins (cephalexin, cefixime) 4
• Amoxicillin-clavulanate 4, 8

Important: Fluoroquinolones and third-generation cephalosporins should be avoided for simple cystitis due to their role in selecting multidrug-resistant organisms and their importance in treating life-threatening infections 6

Alternative: Symptomatic Treatment

For women with mild to moderate symptoms, symptomatic therapy with NSAIDs (e.g., ibuprofen) may be considered as an alternative to immediate antibiotics. 1, 3

• Supportive care with analgesics while awaiting urine cultures is reasonable 1
• Risk of complications from delayed treatment is low 3
• This approach reduces unnecessary antibiotic exposure 1

Treatment Duration

• Uncomplicated cystitis: 3-5 days depending on agent (fosfomycin 1 day, TMP-SMX 3 days, nitrofurantoin 5 days) 1, 2, 3
• Men with uncomplicated UTI: 7 days 2, 3
• Recurrent UTIs: As short as reasonable, generally no longer than 7 days 2

Special Considerations for Men

Men with lower UTI symptoms should always receive antibiotics and require urine culture with susceptibility testing. 3

• First-line options: trimethoprim, trimethoprim-sulfamethoxazole, or nitrofurantoin for 7 days 3
• Consider urethritis and prostatitis as alternative diagnoses 3

Recurrent UTIs

For patients with ≥3 UTIs per year or ≥2 UTIs in 6 months: 1, 2

• Obtain urine culture before each treatment episode 1, 2
• Consider patient-initiated treatment (self-start antibiotics) while awaiting culture results 1, 2
• Preventive strategies: increased fluid intake, vaginal estrogen in postmenopausal women 2

Critical Pitfalls to Avoid

• Do not treat asymptomatic bacteriuria except in pregnant women or before invasive urologic procedures 1, 2
• Do not use azithromycin for UTIs - it does not achieve adequate urinary concentrations 2
• Avoid fluoroquinolones for simple cystitis due to resistance concerns and collateral damage 6, 8
• Do not assume TMP-SMX will work without knowing local resistance patterns 1, 6