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

Treatment of Urinary Tract Infections

For acute uncomplicated UTI 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), with treatment duration generally no longer than seven days. 1

Diagnostic Approach

• Obtain urine culture and sensitivity before initiating treatment in patients with recurrent UTIs (≥2 culture-positive UTIs in 6 months or ≥3 in one year) 1
• For acute uncomplicated cystitis in young healthy women, diagnosis can be made without an office visit or urine culture based on symptoms alone 2
• Patient-initiated treatment (self-start therapy) may be offered to select reliable patients while awaiting culture results 1
• Do not obtain surveillance urine testing or treat asymptomatic bacteriuria in non-pregnant patients, as this fosters antimicrobial resistance and increases recurrence 1

First-Line Antibiotic Selection

The choice among first-line agents should be guided by local antibiogram data, as all three options demonstrate similar efficacy for clinical and bacteriological cure 1:

• Nitrofurantoin monohydrate/macrocrystals: 100 mg twice daily for 5-7 days 1, 2
• Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days 1, 2
• Fosfomycin tromethamine: 3 g single dose 1, 2

Important caveat: Trimethoprim-sulfamethoxazole should only be used if local resistance rates are <20%, and should be avoided in patients recently exposed to fluoroquinolones or at risk for ESBL-producing organisms 1, 3. In recurrent UTIs, resistance rates for trimethoprim (21.4%) and cotrimoxazole (19.3%) exceed acceptable thresholds 4.

Treatment Duration

• Treat acute cystitis episodes with as short a duration as reasonable, generally no longer than seven days 1
• Three-day therapy is appropriate for simple cystitis in women 2, 5
• Single-dose antibiotics are associated with increased bacteriological persistence compared to 3-6 day courses 1
• For men with UTI, 7-14 days of therapy is recommended based on observational data 2

Second-Line Options

Reserve these agents for resistance patterns or allergy considerations 1:

• Oral cephalosporins (cephalexin, cefixime, cefpodoxime-proxetil) 3, 2
• Fluoroquinolones (ciprofloxacin, levofloxacin) - only if local resistance <10% and patient has not used fluoroquinolones in the last 6 months 1, 3
• β-lactams (amoxicillin-clavulanate) - less effective as empirical first-line therapy 2

Critical warning: Fluoroquinolones should be reserved for more invasive infections due to collateral damage concerns and increasing resistance 1, 3, 2.

Complicated UTI Management

For complicated UTIs (structural/functional abnormalities, immunosuppression, pregnancy, male gender, catheter-associated) 1:

• Use combination therapy empirically: amoxicillin plus aminoglycoside, second-generation cephalosporin plus aminoglycoside, or IV third-generation cephalosporin 1
• Treatment duration: 7-14 days (14 days for men when prostatitis cannot be excluded) 1
• For culture-resistant organisms, use culture-directed parenteral antibiotics for no longer than seven days 1

Multidrug-Resistant Organisms

For ESBL-producing Enterobacterales causing UTI 1, 3:

• Oral options: Nitrofurantoin, fosfomycin, pivmecillinam (for E. coli only)
• Parenteral options: Ceftazidime-avibactam 2.5 g IV q8h, meropenem-vaborbactam 4 g IV q8h, or imipenem-cilastatin-relebactam 1.25 g IV q6h 1

For carbapenem-resistant Enterobacterales (CRE) 1, 3:

• Ceftazidime-avibactam, meropenem-vaborbactam, or plazomicin 15 mg/kg IV q12h 1
• Single-dose aminoglycoside may be considered for simple cystitis due to CRE 1

Special Populations

Postmenopausal women with recurrent UTI 1:

• Initiate vaginal estrogen with or without lactobacillus-containing probiotics as first-line prevention

Premenopausal women with post-coital infections 1:

• Low-dose antibiotic within 2 hours of sexual activity for 6-12 months (nitrofurantoin 50 mg, trimethoprim-sulfamethoxazole 40/200 mg, or trimethoprim 100 mg preferred over fluoroquinolones)

Women with diabetes 2:

• Treat similarly to women without diabetes if no voiding abnormalities present

Key Pitfalls to Avoid

• Never classify recurrent UTI patients as "complicated" unless they have structural/functional abnormalities, as this leads to unnecessary broad-spectrum antibiotic use 1
• Avoid treating asymptomatic bacteriuria except in pregnant women or patients undergoing invasive urinary procedures 1
• If symptoms persist despite treatment, repeat urine culture before prescribing additional antibiotics 1
• Consider antibiotic resistance patterns in both the individual patient and community (local antibiograms) when selecting empiric therapy 1